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RESEARCH IN CHINA 

IN THREE VOLUMES AND ATLAS 



VOLUME TWO 



SYSTEMATIC GEOLOGY 



by 
BAILEY WILLIS 




WASHINGTON, D. C. 
Published by thr Carnegie Institution op Washington 
J? July, 1907 



210824 

CARNEGIE INSTITUTION OF WASHINGTON 
Publication No. 54 (Volume 2) 



• » 



• •• 

• • • 






• • • • 
« • •• • • 

« . . . • 

• t • • • 



PRESS OF GIBSON BROTHERS, 
WASHINGTON, D. C. 



CONTENTS. 



Introduction . 
Chapter I. — Archban 



PAOB. 

v 
i 



Chaptbr II. — Protbrozoic 3 

Proterozoic Strata 3 

Wu-t'ai System (Eo-Protcrozoic) 4 

Hu-t'o System (Neo-Proterozoic) 7 

Pre-Sinian Rocks of Central China 13 

Ancient Metamorphic Rocks beyond China 20 

Pre-Sinian Diastrophism 24 

Pre-Sinian Unconformity 31 

Chaptbr III.— Early Palbozoic 35 

Sinian System (Cambro-Ordovician) 35 

The name and its application 35 

Sinian in China 37 

Lower Sinian 37 

Nan-t'ou tillite 39 

Middle Sinian, Kiu-lung group 40 

Upper Sinian 42 

Sinian in general 43 

Post -Sinian Diastrophism 49 

Chaptbr IV. — Middle Palbozoic 53 

Siluro-Devonian Strata of China 53 

Middle Paleozoic Strata beyond China 59 

Middle Paleozoic Diastrophism 66 

Pre-Carboniferous Unconformity 67 

Chaptbr V.— Latb Palbozoic 71 

Carboniferous Strata 71 

Marine Carboniferous 71 

Continental Carboniferous 75 

Chaptbr VI. — Pbrmo-Mbsozoic .... 77 

Transition from Paleozoic to Mesozoic 77 

Theoretical considerations 77 

Permo-Triassic Strata 80 

Angara series 80 

Central China 83 

Jurassic 85 

Permo-Mesozoic Diastrophism 89 

Chaptbr VII. — Continental Asia 95 

Cretaceous 95 

Tertiary and Quaternary 96 

Chaptbr VIII. — Continental Structure of Asia 115 

Hypothesis of Continental Structure 115 

Continental Elements of Asia 118 

Tangential Compression 123 

ni 



LIST OF ILLUSTRATIONS. 

PAGE. 

Plate i. — Geologic Map of Parts of Chi-li and Shan-si, after V. von Richthofen, Bailey Willis, 

: and Eliot Blackwelder > i 

Plates 2 and 2a. — Geologic Route Map, Shcn-si and Ssi-chuan, after Bailey Willis and Eliot Black- 
welder 1 

Plate 3. — Southern Asia during the Protcrozoic Km 35 

4. — Southern Asia during the Sinian Period 53 

5. — Southern Asia during the Middle Paleozoic 71 

6. — Southern Asia during the Carboniferous Period 77 

7. — Hypsometric Map of jChina and Adjacent Regions, showing the Effects of Tertiary and 

Quaternary Diastrophism without regard to Results of Erosion 115 

8. — Continental St met ure of Asia 123 



ERRATA. 



Page 17, line 5, read 1903-04 for 1904-05 
Page 49, line 24, read later for late. 



INTRODUCTION. 



The exjtedition to China carried out in 1903-04 under the auspices 
of the Carnegie Institution of Washington gathered certain observations 
relating to the geology of that country, which are stated in detail under 
the general subject of descriptive geology, in volume 1, part 1, of these 
contributions. The same material is treated in this volume, but from the 
standpoint of systematic continental history. Repetition has been avoided, 
so far as is consistent with the presentation of the general subject. Other 
sources of published information have been freely consulted and are referred 
to in connection with the discussions. 

The subject-matter of this volume is classified primarily according to 
geologic eras or periods, and secondarily by broad areas of which China 
proper is the central region. Thus the reader will find that each chapter 
treats of the geographic condition of southeastern Asia during a particular 
age, and that successive chapters trace the sequence of changes from age to 
age. Only the great events of continental history are distinguishable on 
the basis of existing knowledge, but they suffice to show that the present 
continent is an aggregation of land masses which, from time to time, have 
been forced into union with one another. This generalization has already 
been stated by [Suess, who, in cooperation with Neumayer, developed the 
recognition of the great mediterraneans which formerly divided Eurasia. 

This study of Asia has been carried on with comparative studies of 
North America and Europe, and has led to theoretical views regarding 
continental structure and development which have a broad application. 
They are briefly stated in a closing chapter. 

Many associates have helped me toward an understanding of the prob- 
lems involved, and I desire to express my appreciation of aid received from 
geologists and physicists alike. An especial debt is due the two great 
leaders in the modern advance of geological philosophy, Chamberlin and 
Suess, from whose works and personal suggestion I have derived the 
highest inspiration. Their assistance is none the less earnestly appreciated 
because I have been compelled to a somewhat divergent view in theoretical 
questions of continental development. 

Bailey Wilus. 
Washington, D. C, February 25, 1907. 

v 



CHI-LI £&Afc-S5 



RESEARCH IN CH 




LEGEND 
SEDIMENTARY ROCKS 







UNCONFORMIT 



wm] measures 
UNCONFORMITY 



UNCONFORMITY 



UNCONFORMITY 

METAMORPHIC ROCKS 



UNCONFORMITY 



f | 



KfcKKAh:*H n-s ■■»::< 




RESEARCH IN CHINA 




• •• 

• •••„• 









CHAPTER L— ARCHEAN, 



The term Archean has been used in Asiatic geology by different writers 
to cover various metamorphic but usually ancient rocks. Generally it is 
applied to any highly metamorphic or igneous rocks which are older than 
the oldest clearly recognized sediments of any particular district. In the 
literature " Archean' ' thus covers rocks which range in age from the very 
earliest pre-Paleozoics observed in the continent to Paleozoic, or possibly 
even Mesozoic strata, where these have been greatly altered. Moreover, 
the intrusives have commonly been grouped with the schists, although 
they are certainly somewhat younger, and it is sometimes difficult to say 
how much younger. Thus, granites which n?av be of Paleozoic or Mesozoic 
age are classed as pre-Paleozoic. 

In these volumes the term Archean is applied to a basal mass of gneisses 
and schists, which is also designated the T'ai-shan complex. It is regarded 
as basal because it underlies all other recognized groups and is separated 
from them by an unconformity of a most distinct and profound character; 
moreover, it is fundamental among rock masses known at the surface, 
because it is itself apparently bottomless. Nothing distinct from it and 
older than it has as yet been identified. 

The T'ai-shan complex is not everywhere followed by rocks of the 
same age, the geologic record being incomplete in China as elsewhere. In 
the Wu-t'ai district of northern Shan-si, it underlies the Shi'-tsui group of 
the Wu-t'ai schists, probably the oldest group of sedimentary deposits 
identified in Asia. The most probable rough correlation places this sequence 
in parallelism with the lower Huronian and Keewatin of the Lake Superior 
region of North America.* 

In northeastern China, in the province of Shan-tung, is the type locality 
of the T'ai-shan complex, Mount T'ai. The most ancient rocks are there 
overlain by Lower Cambrian strata and the pre-Cambrian sediments are 
wanting; correlation with the Archean of the Wu-t'ai district is based on 
similarity of lithologic and structural characters, which are common to all 
the occurrences which we have classed as T'ai-shan and are not shared by 
any other rock masses of known superior position in the geologic scale. 

♦Report of special committee for the Lake Superior Region, Chicago Journal of Geology, vol. xiii, 
P. 89. 1905. 









- • • 

• • • 



••• • 



• "• 






> 






• • t 



• • •. • 






.2 RBSSARCH IN CHINA. 

The lithologic and structural characters of the T'ai-shan complex 
are those of the Archean of the Lake Superior 'region of North America, 
as defined by Van Hise. The rocks are chiefly metamorphic schists and 
gneisses of indeterminate original character; associated with them is a 
large proportion of metamorphosed igneous rocks and a very small pro- 
portion of metamorphosed sediments; and the metamorphics are intruded 
by granites, which are relatively young, though in large part probably 
pre-Cambrian. 

The structure of the gneisses and schists is exceedingly intricate; it 
is characterized by a universal schistosity; by a common banding; by com- 
plex shearing, thinning, thickening, plication, and flow of bands ; and such 
intricate arrangement of the very variable petrographic fades of the schists 
and gneisses as makes impossible any structural study by usual strati- 
graphic methods. 

These lithologic and structural peculiarities of the T'ai-shan complex 
serve to distinguish it unmistakably from the oldest pre-Cambrian sedi- 
ments, the Wu-t'ai system, even though the latter are intensely metamor- 
phosed. 



CHAPTER IL— PROTEROZOIC 



PROTEROZOIC STRATA. 

We recognize two principal systems of stratified rocks of the Protero- 
zoic era in northern China, the Wu-t'ai and the Hu-t'o or Nan-k'ou systems. 
The Wu-t'ai was observed and named by von Richthofen; the other he did 
not distinguish from the Sinian, of which he thought it a conformable part, 
and he described it as "Untersinisch." In certain sections and probably 
generally, there is an unconformity between the "Untersinisch" and the 
"Obersinisch," and it seems desirable to separate them by restricting the 
term Sinian to upper or Obersinisch and giving a new name to the lower 
or Untersinisch.* Nan-k'ou is an appropriate name, which may be applied 
if we correctly understand von Richthofen's section at the celebrated pass 
northwest of Peking. Hu-t'o is a name we gave to a series which is 
probably the equivalent of the Nan-k'ou, though it differs somewhat in 
the character of the strata. The matter is discussed in a later paragraph. 

Proterozoic rocks are best exposed in China, so far as yet known, in a 
mountain range in northern Shan-si, called the Wu-t'ai-shan. This name, 
which means Five Platform Mountains, is derived from the five highest 
summits in the region, Pei'-t'ai or North Table having an altitude of 10,045 
feet. The range is deeply incised, and the canyons expose remarkably 
distinct sections of ancient metamorphic rocks, comprising the basal or 
T'ai-shan complex (Archean) and the Wu-t'ai system, eo-Proterozoic. 
The latter is thought to be roughly correlative in age and duration and 
complexity with the Huronian of Canada. 

On the southeastern flank of the Wu-t'ai-shan is a wide area of hills 
and valleys, which we have called the Northern Loess Basins. The general 
altitude is 3,500 to 5,000 feet above sea. Rocks of the early Proterozoic, 
Wu-t'ai, system constitute part of the surface, but a younger pre-Cambrian 
system of but slightly altered quartzites, slates, and siliceous limestones 
covers a larger area. This neo-Proterozoic system we have called the 
Hu-t'o, a local name, which may ultimately be replaced by the term Nan- 
k'ou of von Richthofen or that of Nan-shan of L6czy. 

In view of the better, though still incomplete, knowledge which we 
have of the Proterozoic in the Wu-t'ai as compared with notes of occur- 
rence of similar rocks elsewhere, we may take the Wu-t'ai sections as types. 

♦In a personal conference in Berlin, March, 1905, von Richthofen agreed orally to the desirability of 
making this distinction, but his views were not put in writing, so far as I am aware. 



RESEARCH IN* CHINA. 



WU-r AI SYSTEM (EQ-PROTEROZOIC). 

Rocks of the Wu-t'ai system constitute much off the Wu-t'ai-shan, a 
short but high mountain range in northern Shan-si. longitude H3°30 f E. v 
latitude 39° X. Von Richthofen crossed the mountains in December, 
1871, and clearly observed the existence of a series of strata which he had 
not previously seen in the course of his extended journeyings ; nor are they 
elsewhere known in equal mass. During the stormy December weather 
which he met the conditions were most unfavorable for observation, and 
his route crossed only a part of the Wu-t'ai rocks, that mass of chlorite 
schists which we consider the upper part and call the Si-t*ai formation. 
The lower series of mica schists, quartzites, and marbles he did not see. 

Von Richthofen placed the Wu-t'ai system in the Huronian, using 
the latter term, as was commonly done thirty years ago, to suggest pre- 
Paleozoic metamorphic rocks of green color.* He does so with reserve, 
however, and the stricter usage of the term as it is now adoptedf does not 
permit us to maintain an exact correlation. Yet there is a certain paral- 
lelism in stratigraphic position and history, as well as likeness in rocks, 
which invites comparison of the Wu-t'ai and the Huronian, as will appear 
in stating the facts as we now understand them. 

Our own opportunities for study of the Wu-t'ai system were limited 
practically to a single section and a few isolated localities. In volume 1 
we have stated our inference regarding the stratigraphic sequence and 
structure as provisional only, and we commend to some future investigator 
the almost unequaled exposures of ancient sedimentary and igneous rocks 
which represent one of the earliest intelligible records of Asiatic history. 

A provisional classification of the Wu-t'ai and limiting systems in the 
type locality is as follows : 



Hu-t'o system 
(Smy-ProUroioic) 



Tung-yu limestone \ g^ ^^^^ ^ q^^. 



Wu-t'ai system 
(Eo-Proteroxoic) 



Tdu-ts'tin slates 

Unconformity 
Si-fai 



Unconformity 
Xan-t'ai series 

Unconformity 
Shl-tsui 



Tai-shan complex 
(Arckean) 



Unconformity 



Chiefly chlorite schist ; quartzite conglom- 
erate at the base. 

Siliceous marble, jasper, quart zite, and 
schist. 

Mica schists, gneiss, magnetite quartzite, 
and basal feldspathic quartzite. 

Basal complex of varied gneisses and 
younger intrusfves. 



A brief account of the successive elements of the Wu-t'ai section fol- 
lows (see atlas sheet DI and plate xvni, volume 1, part 1) . 

•China, vol. n, *p. 377. 

t Report of International Committee, Chicago Journal of Geology, vol. zm, 1905. 



wu-t'ai system, bo-protsrozoic. s 

That there is an unconformity at the base of the ShI-tsui series, sepa- 
rating it from the T'ai-shan complex, we do not doubt. The distinction 
between the stratified schists and quartzites of sedimentary origin and the 
very intricate complex of parallel bedded injection gneisses is decided when 
they are contrasted in extensive sections. But the exact contact between 
the two is not readily recognized. In a ravine south of the T'ai-shan-ho 
we found a peculiar quartzite containing large crystals of red feldspar, 
which is a recrystallized arkose, occurring at or near the base of the Shi'-tsui 
series, on or close to the T'ai-shan gneiss, from which the material was 
probably derived by erosion. The immediately underlying stratum is a 
mica schist of indeterminate origin. The feldspathic quartzite grades 
upward through quartzite containing some mica and but little feldspar, 
into mica schists, which present great variety of mineralogical composition 
and are in turn succeeded by quartzites which are in part magnetic. The 
section of sediments, which has a length of eight miles, is interrupted by 
a mass of augen-gneiss that is probably intrusive. The dip of the Shi-tsui 
strata in this section is from 30 to 70 to the northwest, and the repetition 
of the quartzite on two sides of a great body of mica schists is such that 
the probable structure is a syncline overturned toward the southwest. 

The augen-gneiss above referred to extends for three miles along the 
T'ai-shan-ho. It has the uniformity of composition of a batholite and 
appears to be an intrusive which has suffered shearing and metamorphism 
with the sedimentary Wu-t'ai rocks. Northwest of it occur the strata of 
the Si-t'ai and Nan-t'ai groups. 

Nan-t'ai and Si-t'ai are two of the five peaks of the Wu-t'ai-shan, 
each of which is composed chiefly of the strata named after it. 

Strata of the Nan-t'ai group are siliceous marble, gray to black or 
red quartzites, and schists, chiefly of chlorite and muscovite. They are 
also garnetiferous and staurolitic. They occur on the southeast slope of 
the Wu-t'ai range and are well exposed in the canyons above Shang-ho- 
miau. The structure shows two or more closed synclines, overturned 
toward the south, and overthrusts which eliminate the anticlines. The 
sequence, as we interpret it, consists of siliceous and muddy sediments below 
and calcareous deposits above. It may be continuous with or distinct 
from the Shi-tsui. The two groups of rocks were not seen in contact. 

The Si-t'ai group, comprising most if not all of the sequence seen by 
von Richthofen, forms the mass and northern slope of the Wu-t'ai-shan. 
It is a great body of green schists, chiefly chloritic, with beds of quartzite 
containing magnetite, and coarse conglomerate of quartz and quartzite 
cobbles at the base; all as he described it.* The relations with the Nan- 
t'ai group are well exposed in the canyons on the south slope of the range. 

* China, vol. n, p. 364. 



6 RESEARCH IN CHINA. 

We there find the conglomerate duplicated by overthrust, but overlying in 
regular sequence the Nan-t'ai quartzites, and grading from conglomerate 
through quartzite upward to schist, after the fashion of a passage from 
basal conglomerate to fine muddy sediments. The pebbles in the conglom- 
erate consist chiefly of quartz and quartzite, the latter being of varieties 
that occur in the Nan-t'ai group, together with some of granite. Hence we 
infer that the rocks below the Si-t'ai had been folded and eroded before 
that series was deposited. The conglomerate, consisting as it does almost 
entirely of large rounded quartz and quartzite pebbles, contains the 
remains of a deposit that had been concentrated from a more complex 
constitution. Before metamorphism it may have closely resembled the 
bed of quartz cobbles found at the base of the Potomac formation of the 
Atlantic coast, and may have resulted, as that deposit did, from a prolonged 
cycle of erosion which ended in consequence of a marine transgression across 
a peneplain. Moreover, in the western part of the Wu-t'ai-shan, no groups 
corresponding to the Shi-tsui and Nan-t'ai groups were seen between the 
T'ai-shan complex and Si-t'ai schists. This fact and the presence of the 
granite pebbles in the conglomerate suggest an overlap of Si-t'ai strata 
beyond the older Proterozoic rocks. 

The greater part of the Si-t'ai group consists of green schists colored 
chiefly by chlorite. Stratification is obscured by schistosity and the struc- 
ture can not readily be made out. It is probable that several isoclinal folds 
occur, overturned toward the south and separated by overthrust faults. 

On the summit of Pei'-t'ai is a small area of biotite gneiss, which may 
be the highest stratum of the Si-t'ai group preserved in a syncline, but we 
were not able to determine conclusively what the relations to the adjacent 
green schists actually were. The gneiss may be an intrusive body. 

Returning to the analogy which exists between the Wu-t'ai and Huron- 
ian systems, I may point out some of the parallel relations. The Lower 
Wu-t'ai (Shi-tsui group) rests unconformably upon the basal T'ai-shan 
complex, as the lower Huronian does on the Archean (Keewatin) gneiss. 
The Nan-t'ai group overlies the Shi-tsui and may be separated from it by 
an unconformity, as the middle Huronian is from the lower. The two 
series were similarly composed of siliceous, clayey, and ferruginous sedi- 
ments, which have undergone intense metamorphism and become schists of 
varied constitution. The upper Wu-t'ai (Si-t'ai group) is unconformable 
to the middle Wu-t'ai as the upper Huronian is to the middle Huronian. 
The upper group in each case consists largely of chloritic schists associated 
with ferruginous quartzites. [Both the Wu-t'ai and the Huronian series 
have been affected by some igneous intrusions, which occurred before the 
strata were deformed by shearing, and also penetrated by later dikes. 
These are but analogies, yet they serve to suggest a parallel in the ancient 



LATER PROTEROZOIC. 7 

history of Asia and North America, which extends to successive events of 
erosion, deposition, and deformation. The general relations to the Archean 
and neo-Proterozoic are similar in both continents, and the effects may well 
have been due to a general terrestrial cause which became active at about 
the same times, in regions remote from one another. 

Before discussing the occurrence elsewhere in Asia of pre-Cambrian 
rocks, which may be equivalent to the Wu-t'ai, I describe the next younger, 
the Hu-t'o system. 

HU-T'O SYSTEM (NEO-PROTEROZOIC). 

All of the rocks of the Hu-t'o system are sedimentary strata : conglom- 
erate, quartzite, shale, and limestone, which resemble the unmetamorphosed 
Paleozoic rocks more nearly than they do the Wu-t'ai schists. The physi- 
cal events which intervened between the close of the Wu-t'ai period and 
the beginning of the Hu-t'o involved greater changes and probably longer 
time than those which occurred 'after the Hu-t'o and before the Sinian ; 
but the presence of a rich fauna in the Sinian seas distinguishes that period 
from the preceding time, during which the life forms, though probably 
numerous, did not generally become fossil. The nearest relations of the 
Hu-t'o system are with the Belt terrane of Montana, and it is probable that 
pre-Cambrian fossils * such as have been found in the Belt may eventually 
be discovered in the Hu-t'o. 

The Hu-t'o rocks occur in typical development in the district of Wu- 
t'ai-ih£n, in northern Shan-si, where they form the southwestern part of the 
Wu-t'ai-shan and the hills about the Northern Loess Basins as well as along 
the Hu-t'o river. They occupy a broad synclinorium and lie between the 
Wu-t'ai schists and Sinian strata, in unconformable relations to both 
systems. Although the contact with the underlying Wu-t'ai series must 
be extensively exposed in the mountains southwest of the upper T'ai-shan-ho 
and also north of the Loess Basins, we did not see it. It was covered by 
loess in each of the sections along which we crossed it, and we did not recog- 
nize the distinct position of the unfamiliar Hu-t'o rocks in time to search 
for the contact. There can, however, be no doubt of an unconformity 
between the schists of the Wu-t'ai and the little-altered, slightly slaty beds 
of the Hu-t'o. After the Wu-t'ai sediments had been deposited they were 
folded, depressed by folding or subsidence to a notable depth, intruded by 
large igneous masses, and deformed under great pressure, so that their 
original structure was replaced by schistosity and their constituents were 
recrystallized. The Hu-t'o rocks suffered none of these changes. They 
were deposited only after the schists had been exposed by uplift and deep 
erosion. Obviously an interval of the first magnitude intervened. 

♦Pre-Cambrian fossiliferous formations, C D. Walcott, Bull. G. S. A., vol. x, p. 199, 1899. 



8 RESEARCH IN CHINA. 

Observations of the contact between the Hu-t'o and the overlying 
Sinian show clearly that the former were folded, intruded by dikes, and 
eroded, before the latter were laid down.* 

The Hu-t'o strata apparently constitute a sequence, which consists of 
conglomerate and sandstone, clay slates, and siliceous calcareous strata. 
The entire series is thinly bedded and the three elements (sands, clays, 
and carbonates) occur interbedded. In the type locality we observed a 
number of partial sectionsf which we could not connect on account of the 
extensive covering of the Huang-t'u, the loess formation. The sandy rocks 
appear to preponderate near the base and the limestones increase in pro- 
portion toward the top. This distinction appeared to be sufficiently marked 
to separate a lower argillaceous group from an upper calcareous one, and 
we have described the former as the T6u-ts'un slates and the latter as the 
Tung-yii limestone. The division has local significance only. 

The T6u-ts'un slates comprise the lowest beds of the Hu-t'o series and 
have a thickness of not less than 3,500 feet, 1,000 meters; they may reach 
5,000 feet, 1,800 meters. The principal strata are earthy gray to purplish 
slates, or locally phyllites, with which occur thin layers of buff to pink 
dolomite and siliceous limestone. The lowest beds seen, which we take 
to be near the base of the series, are of red and gray quartzite with local 
layers of conglomerate. 

The Tung-yii limestone includes all the upper part of the Hu-t'o 
system. The characteristic rock is gray limestone, in which chert is usually 
present in notable quantity and often in masses or sheets. The massive 
beds of limestone vary in thickness from 10 feet to 500 feet, 3 to 150 meters, 
or more, and strata of gray to red slates or phyllites occur between them. 
The sequence is very like that of the underlying T6u-ts'un group, but the 
relative proportions of slate and limestone are reversed. The thickness 
of the Tung-yii limestone is probably 3,000 feet, 900 meters, or more. 

Throughout northern China there is a limestone formation which is 
lithologically identical with the heavy beds of the Tung-yii group, and 
occupies the stratigraphic position of the whole Hu-t'o series. We regard 
it as the equivalent of the Hu-t'o, but have given it the distinctive name of 
Ta-yang from a village in Chi'-li near which it is well developed, longitude 
H5° 50', latitude 38 45'. 

The Ta-yang is a dark-gray, massive limestone, which is distinguished 
from the very similar Sinian limestones by abundance of chert and absence 
of fossils. The formation is exceedingly uniform in lithologic character; 
the greater or less proportion of chert and the occasional occurrence of 
white quartzite being the chief variations. A notable characteristic is found 

♦Vol. 1, p. 136. 

t Ibid., pp. 123-125. 



LATER PROTEROZOIC. 9 

in curved and minutely contorted laminae of flint, the contortion of which 
appears to be independent of local deformation of the strata. Similar 
bands have been noticed in the Siyeh limestone of the Belt formation, Mon- 
tana.* They are noted by L6czy as occurring in the Nan-shan sandstone 
of Tibet. f Similar forms, described by Stose in Cambrian limestones 
of the Appalachian Valley, are classed as Cryptozoan proliferum Hall .J 
Whether the peculiar structures are in some cases mechanical or organic is 
not known, but they have a long range — from late Proterozoic to Ordovician. 
They have not, however, been seen in the Sinian. Neither have the oolitic 
and conglomeratic phases of the latter been observed in the Ta-yang. 

The thickness of the Ta-yang in a partial section measured by Black- 
welder west of the type locality exceeded 1,200 feet, 360 meters, by an 
unknown amount. Willis observed a section northwest of T'ang-hi6n, 
Chi'-li, which, though interrupted by at least two normal faults, appeared 
to include 6,000 feet, 1,800 meters, of the limestone.§ The thickness is, 
no doubt, several thousand feet. 

At the base of the Ta-yang limestone is usually a thin stratum of 
slate or phyllite, which rests in marked unconformity upon the T'ai-shan 
complex (Archean). No doubt the limestone may occur in unconformity 
on the Wu-t'ai schists, as does its probable equivalent, the Hu-t'o system, 
but we did not observe any such instance. The occurrences we saw were 
at points west of Pau-ting-fu, Chi'-li, and have been described in detail.|| 

A contact of the Ta-yang limestone with strata of Sinian age was 
observed at Nan-t'ang-mei, Chi'-li (see vol. 1, fig. 27, and atlas sheet F I). 
A very heavy bed of residual chert pebbles, derived from the pre-Cambrian 
limestone there, occurs beneath quartzite and black argillite, which are con- 
formable to the overlying Sinian and which, though lithologically peculiar, 
are believed to belong to that system. The body of residual chert is 
regarded as an accumulation on the eroded surface of the Ta-yang, which 
was therefore folded and exposed before the lowest Sinian stratum was 
deposited. 

Having thus described the Ta-yang limestone and its relations as we 
saw them, I give the following sections from von Richthofen, in which 
he noted strata that closely resemble it in character and stratigraphic 
position and which we consider to be its equivalents. These sections also 
include the Sinian, namely, von Richthofen's Obersinisch, and the Ta- 
yang equivalents are described by him as the Untersinisch. He did not 

* Stratigraphy and Structure of the Lewis and Livingston Ranges, B. Willis, Bull. G. S. A., vol. xin, 
P. 305, 1902. 

tRe»e des Grafen Szechenyi in Ostasien, vol. 1, p. 553- 
(Chicago Journal of Geology, vol. xiv, pp. 210 and 217, 1906. 
§Fig. 27, vol. i, page 131. 
IVol. 1, p. 130. 



IO 



RESEARCH IN CHINA. 



observe an unconformity between the two, but our observations of other 
sections, nevertheless, lead us to infer that an unconformable relation is 
general between the Ta-yang and the Sinian systems. 

Von Richthofen's first section is across the Nan-k'ou range, north- 
west of Peking, en route to Kalgan. 

SECTION IN THB NAN-K'OU RaNGB (VON RiCHTHOPBN).* 



Description of the rocks. 



m Evenly bedded limestones without chert , 
dark gray to blackish; fine-grained; 
break splintery and conchoidal, some- 
times uneven. Beds 2 to 1 2 inches thick, 
seldom more, well separated from one 
another. Non-fossiliferous. Here occur 
the limestones with horizontally em- 
bedded, fiattish, rounded bodies which 
give worm-like outlines in cross-section. 
The bodies here consist mostly of dense 
black, the matrix of crystalline lime- 
stone. These " Wurmkalke" are every- 
where characteristic of an upper horizon. 
Another typical rock is greenish splin- 
tery limestone. Total thickness 

1 Globulitic limestones, clear gray to black. 
Globulites mostly size of oat kernels, 
seldom as large as peas. Beds 2 inches 
to 2 feet thick. Trilobites abundant 

k Green strata 

i Globulitic limestones like 1, predomin- 
ating, with dense homogeneous lime- 
stones interbedded 

h 5. Red clay shales 120' 

4. Gray limestone 80' 

3. Red strata 80' 

2. Dense siliceous limestones of fiat con- 
choidal fracture, very evenly bed- 
ded; whitish, greenish, reddish; 
prevailingly greenish-white . 200' 
1. Red clay shales ioo' 

g Gray, dense limestone, in part fine- 
grained crystalline 

f Black and gray sandy clay shales and 
sandy, in part micaceous slates, partly 
even, partly curved. (Krummschalig.) 
Yellow sandstone with iron ore 

e Whitish-gray, fine-grained, crystalline lime- 
stone, with interrupted inter bedding and 
knots of black flint 

d Blue crystalline siliceous limestone, in part 
pure, in part interbedded with thick 
beds of flint. Thickness not determined, 
but great. 

* China, vol. n, p. 306. 



Thickness 
(feet). 



2000 



500 
80 



1500 



580 
400 



500 



2500 



Equivalents in terms of this volume. 



The limestone (m) comprises strata which 
are characteristic of the Tsi-nan and 
Chau-mi-tien limestones. The non-fos- 
siliferous condition is specially marked in 
the former, but fossils are not common in 
the latter. The "Wurmkalke," conglom- 
eratic limestones, are well developed at 
the base of the Chau-mi-tien. A distinc- 
tion between the two would scarcely be 
recognized in reconnaissance. The thick- 
ness is less than their combined volume, 
but the upper part of von Richthofen's 
section is covered. 



Strata comprised under i, k, and 1 corre- 
spond to the oolitic limestones and green 
shales of the Kiu-lung group of Shan-tung. 
The thickness of oolitic limestone is four 
times any measure which was there seen. 
It may be overestimated, but if correct 
does not affect the probability of close 
correlation. 

Beds 1 to 5 inclusive (h) are very character- 
istic of the Man-t'o formation of Shan- 
tung. The 200-foot limestone bed is 
much thicker than any occurring there, 
but holds a stratigraphic position like 
that of a thin layer in the type section. 



Beds f and g are unfamiliar ; they appear to 
be upper members of the Ta-yang lime- 
stone, which were eroded in the sections 
we observed. 



Beds d and e are typical Ta-yang limestone, 
and in view of the great thickness, the 
lithologic identity, and similar position 
below the Man-t'o, we feel confident of 
their being equivalent to that formation. 



LATER PROTBROZOIC, NAN-K'OU TBRRANB. II 

The close comparison practicable between the observations which 
von Richthofen made in rapidly crossing the Nan-k'ou pass and the detailed 
sections we were able to measure in Shan-tung bears testimony to the accu- 
racy and painstaking character of his work. The differences are not greater 
than might be expected in sections 300 miles apart, and all the character- 
istic earmarks of the formations are noted by him in their appropriate 
succession. Although he was not able to collect fossils, he observed their 
occurrence at horizons elsewhere abundantly fossiliferous. That von Richt- 
hofen did not see any unconformity between the Sinian and the strata 
d, e, /, g, which we assign to a pre-Sinian system, is not surprising. He 
remarks that the dip in the red strata (basal Sinian) was variable. The 
limestones are very much alike in the two systems, and even one who is 
looking for an unconformity may easily pass the contact in crossing a single 
section en route to "distant night quarters which were difficult to reach." 
Negative evidence of that kind has little or no weight. Nevertheless, it 
is obvious that the strata in the Nan-k'ou pass are less closely folded than 
in the vicinity of Si-ta-yang, where we observed the pre-Sinian rocks, and 
it is possible that an unconformity of dip may not exist. But even if the 
strata be conformable, it would still, in our judgment, be undesirable to 
extend the term Sinian to the great body of siliceous limestones below the 
Man-t'o shale, the first formation laid down in consequence of the trans- 
gression with which the Sinian period opened. 

If the equivalency of the Ta-yang limestone with that exposed in the 
Nan-k'ou pass be eventually established, it will be desirable to abandon 
the term Ta-yang for Nan-k'ou as the name of the system. Nan-k'ou is 
the locality where the strata were first distinguished; they are apparently 
more completely represented there. The locality is at once well known 
and accessible, it being on the highway from Peking to Kalgan. Believing 
the strata to be equivalent, I regard Ta-yang as a local name that in 
systematic discussion should give way to Nan-k'ou. Cherty limestones of 
the Nan-k'ou terrane are described by von Richthofen as outcropping in 
a ridge adjoining the Nan-k'ou range,* but the section is incomplete. 

In southern Chi-li, near "Hwo-lu-hsien," longitude 114 30', latitude 
38°+, a section of limestones is exposed in the "Hsi-p'ing-shan" moun- 
tains bordering the Great Plain, which von Richthofen describes as follows 
from above downward: 

Firm sandstone, white and gray. 
Crystalline limestone. 

(Interruption.) 
Greenish gray, brightly colored, ringing. * bin-bedded siliceous limestones; interbedded 
with various sorts of strata. 



* China, vol. 11, p. 343. 



12 RESEARCH IN CHINA. 

Globulitic and conglomeratic ("Wurmkalk") limestones. 
Thin-bedded limestones, red and green. 
Red shales. 

(Interruption.) 
Crystalline limestone with nodules and layers of flint. 

(Interruption.) 
Alternation of crystalline^ thin-bedded, limestone, including thin layers of flint, with 
quartzite, epidote rock, red sandstone, etc. 

(Interruption.) 
Gray crystalline limestone. 

This section does not present sufficient continuity to enable us to 
identify the several formations precisely, but the sequence of three typical 
groups of strata, cherty limestone, red shale, and characteristic Sinian 
limestone, is apparent. The cherty limestones are evidently the same as 
the Nan-k'ou terrane. 

With reference to the locality at which we observed the Ta-yang lime- 
stone, the two sections cited from von Richthofen lie respectively, the 
Nan-k'ou northeast, distant about 200 kilometers, and the Hsi-p'ing-shan 
southwest, 80 kilometers. The Ta-yang locality thus lies between the two, 
and all three occur in the foothills that bound the Great Plain on the west. 
The greater part of the Nan-k'ou system in this northeast-southwest 
trend is siliceous limestone, which, from its extent and unusual thickness, 
is obviously a marine deposit. 

Both von Richthofen and Blackwelder have observed the older sedi- 
mentary rocks of Liau-tung. After describing the fundamental gneiss 
the former sums up his observations* by enumerating two groups, namely, 
black quartzites and hornblende schists, which are intruded by granites 
and greenstones and weather down to a rich soil and rolling landscape; 
and the Ta-ku-shan series, consisting of firm, well-stratified quartzites of 
yellowish and whitish tints, together with clay schists, mica schists, and 
crystalline limestone. The schists and limestone occur in intimate but 
indeterminate relations with the quartzites. The schists attain a thickness 
of several thousand feet; the limestone is of limited or local occurrence 
only. These strata are intruded by the Korea granite, and unconform- 
ably overlain by a red cross-bedded sandstone with occasional conglomer- 
atic layers, the Yung-ning sandstone. 

According to von Richthofen, the Yung-ning sandstone belongs to his 
"Untersinisch. ,, t Blackwelder, J on the other hand, regards it as a local 
development of the Man-t'o shales, the red littoral deposit that marks the 

♦China, vol. n, p. 106. 

-\Ibid., vol. 11, pp. 73 and 109. 

X Research in China vol. 1, p. 95. » 



PROTEROZOIC, CENTRAL CHINA. 13 

Sinian (Cambrian) transgression; and if that be the case it falls into von 
Richthofen's "Obersinisch." 

In Shan-tung von Richthofen distinguished a metamorphic series 
which included limestone and certain quartzites. The two were not seen 
in contact and their relations remain indeterminate between themselves 
as well as to similar metamorphic formations elsewhere. The sequence, 
which includes crystalline limestone, occurs in eastern Shan-tung, between 
Chefoo and Tong-ch6u-fu, with a thickness of several thousand feet. The 
lower part is mica schist, which, higher in the succession, gives place more 
and more to alternating limestone beds which attain great thickness and 
make up the upper part of the system in the "Kung-sun-shan. M This strati- 
graphic sequence resembles that of the lower Wu-t'ai series of Shan-si, and 
the antiquity of the rocks, as judged by schistosity and metamorphism, is 
similar ; but the series may be of some other Proterozoic age. 

The quartzites occur near Ch'ang-kiu-hten, in eastern Shan-tung, and 
constitute a mountain mass cut through by diorite. They are much folded 
in a region where the Sinian is hot, and are of pre-Sinian age, probably 
equivalent to the Ta-ku-shan quartzites, according to von Richthofen. 

PRE-SINIAN ROCKS OF CENTRAL CHINA. 

The typical occurrences of rocks of the Wu-t'ai and Hu-t'o or Nan- 
k'ou systems are confined to the eastern part of the continent. They lie 
2 to 4 of longitude west of the present eastern coast, between the parallels 
of 38 and 40 north. In the same latitude they are 24 to 26 east of the 
central meridian of Asia, which we may take as longitude 90 east. They 
are apparently isolated areas, known only in the mountainous region of 
northwestern China, and may eventually prove to be provincial systems, 
which can not be precisely correlated with terranes of other regions. A 
similar condition exists in North America, where rocks of Proterozoic age 
are known in several widely separated districts, but they have not been 
more closely correlated than as earlier and later Proterozoic. Nevertheless, 
rocks having the lithologic characters of the Wu-t'ai and Nan-k'ou strata 
and holding a somewhat similar position between those which are classed 
as Archean and deposits which are identified as Paleozoic, are known else- 
where in Asia, and it is desirable to place them roughly in parallelism. 

Our own observations are limited to a single section of the Ts'in-ling- 
shan, Shen-si, and the outcrop in the lower Yang-tzi gorges, Hu-pei.* Von 
Richthofen, f L6czy,J and Obrutchov§ are the original observers upon 

♦Vol. 1, pp. 265 and 313. 

t China, vol. n, p. 557 et seq. 

% Reise des Grafen Szechenyi in Ostasien, vol. 1, chapters vn, vm, and tx, 

$ Northern China and the Nan-sban (in Russian). 



4 



14 RESEARCH IN CHINA. 

whom we must chiefly depend. The citations from Russian geologists, 
given by Suess,* are very valuable. 

I take up the occurrences of rocks which may be related to the Wu-t'ai 
and Nan-k'ou systems, in geographical sequence, proceeding from the 
nearer to the more remote. The typical terranes of the pre-Sinian sedi- 
ments in North China are found in the Wu-t'ai-shan, longitude ii4°±:, 
latitude 39°±, northern Shan-si, and in the Nan-k'ou range, longitude 
n6°±, latitude 4i°±, northwestern Chi-li. They have been described in 
the preceding section. 

In central and southern Shan-si, quartzites and schists of typical 
pre-Sinian character occur in the mountains northwest of F<Jn-ch6u-fu, 
longitude n 2°, latitude 37°+, in the Ho-shan, longitude 112 , latitude 36 
to 37 , and in the Fong-huang-shan, longitude 1 io° to 1 1 1°, latitude 35 . 
They appear on anticlines or normal fault-scarps, below Sinian strata. Our 
information regarding them is limited, however, to identification of float 
brought down by streams and distant observations of their characteristic 
outcrops beneath limestone scarps, as neither von Richthofen nor any of his 
successors has seen them at close range in place. Our notes are given in 
volume 1, page 171 et seq. 

A great mountain chain, the Ts'in-ling-shan, stretches from cast to west 
across Central China, between the meridians of 104 and 114 east, about 
700 kilometers southwest of the Wu-t'ai-shan. This barrier range, which 
is regarded as the eastern continuation of the Kwen-lung, consists chiefly 
of Paleozoic and Mesozoic strata. It is the northern margin of a geologic 
province that is distinguished by metamorphism of the Permo-Mesozoic and 
older sediments, which in northern China are unaltered. In this respect 
it bears to that region much the same relation as that which the Sierra 
Nevada of California has to the Great Basin province of Nevada and Utah. 
Within this metamorphic province there occur quartzites, phyllites, and 
even schists, which are in fact of Sinian age or younger, but which have 
pre-Sinian aspects. We are therefore obliged to be cautious in making 
correlations on a lithologic basis. 

The eastern end of the Ts'in-ling-shan is described by von Richthofen 
under the name Fu-niu-shan, and a northeastern outlier of imposing alti- 
tude is the Sung-shan. These heights are in Ho-nan, south of the Huang -ho, 
longitude 113 east, latitude 34°±. In describing the sections which he 
saw in the Fu-niu-shan,f von Richthofen mentions chloritic schists and 
crystalline limestone; less distinctly crystalline and gray-green slates 
(Thonschiefer) and slaty quartzites; and these strata, which are steeply 
folded, are unconformably overlain by coarse conglomerate and sandstone 

* Face de la Tare, vol. m. 

tChina, vol. n, pp. 496-497. > 



EASTERN TS'lN-UNG-SHAN. 15 

in which coal-beds occur. This is the section in the southern ridge, the 
Kiu-li-shan. A range which succeeds on the north consists of crystalline 
limestone, crystalline schists, gneiss, and a large mass of granite. The 
granite rises 2,500 to 3,000 feet, 750 to 900 meters, above the narrow pass; 
it consists of a ground-mass of orthoclase, greenish plagioclase, much quartz, 
some brown mica, and sporadic hornblende of medium texture, in which 
occur crystals of bright flesh-red orthoclase, that have the form of Carlsbad 
twins and attain a diameter of 4 inches. 

The granite is plainly intrusive in the gneiss, which it traverses in 
large dikes. Quartz veins are also extensively developed. Crystalline 
schists intruded by quartz porphyry complete the section of the range on 
the north. Oolitic limestone of Sinian character, but which seemed to 
be unfossiliferous, occurs in a parallel ridge a short distance to the north 
and is unconformably overlain by coal-bearing sandstones. The latter are 
intruded by " greenstones" and porphyritic eruptives. Von Richthofen 
maps the crystalline schists and associated rocks of the region as "gneiss 
and crystalline schists in general," with the color with which he indicates 
the pre-Sinian (Archean) basement. The assignment to a pre-Sinian age 
is borne out by the apparent relation between the metamorphics and the 
unaltered strata classed as Sinian. In the grouping which is adopted in 
this report the predominantly sedimentary rocks of pre-Sinian age fall 
into the Proterozoic and their lithologic associations are with the Wu-t'ai 
system, or possibly with the Hu-t'o. A qualification of this inference lies 
in the intrusive character of the granite and its possible Mesozoic age. If 
the metamorphism is the effect of an episode of deformation with which 
the intrusions are related, and the granite is post-Carboniferous, then the 
schists, quartzites, and crystalline limestones may be Paleozoic. There 
is, however, nothing to sustain this qualification except the fact that post- 
Paleozoic granites occur in the Ts'in-ling-shan. Although not in the 
least gneissoid, and therefore apparently young, the intrusive is in this 
respect, as well as in petrographic constitution, identical with the Korea 
granite of Shan-tung and Liau-tung, which von Richthofen determined 
to be pre-Sinian* and with which he compares it. 

The Sung-shan in Ho-nan, one of China's five holy mountains, was 
seen by von Richthofen from a distance. It is an isolated mass estimated 
by him at 8,000 feet altitude. A principal peak, the Yii-tsai-shan, exhibits 
the form common to masses of the coarse granite, while the main range 
shows those sculptured from crystalline schists. A relatively low ridge, 
the "Hsiung-shan,"onthesouthof the Sung-shan, appeared to the traveler 
to consist of lower and upper Sinian strata resting on a base of schists. 

*China, vol. n, p. 83. 



1 6 RESEARCH IN CHINA. 

Between the meridians 112 and 109 east, L6czy crossed the Ts'in- 
ling-shan on the highway which connects the valley of the Han with that 
of the Wei*. In ascending the <4 Si6-ho M (Siau-ho or Little River) he noted 
several sections of Paleozoic strata, which were not metamorphosed, rising 
between basins of Mesozoic deposits. On the north he next observed graph- 
itic schists, pyritiferous quartzite, and yellow dolomite, which he classes as 
4 * submetamorphic Paleozoic schists. ' ' The description of them* corresponds 
closely with rocks which we observed on the Han and south of it, between 
longitude 108 30' and 109 30' east, and classed as Middle Paleozoic and 
Carboniferous. The observations thus agree. 

After crossing the metamorphosed Paleozoic strata, Loczy came upon 
a broad belt of biotitic schists of monotonous character, with which occur 
dark amphibole schists and gneiss, chlorite gneiss, and lenses of white 
granular limestone. These metamorphosed sediments are intruded by 
massive diorite, coarse-grained amphibole granite, and pegmatite, which 
locally change the schists to hard, fine-grained gneisses. He classes the 
complex under the Azoic or Archean formations. They are unconform- 
ably overlain by slightly coherent conglomerate, sandstone, and shale, of 
Jurassic age; beyond these superjacent beds reappear quartzitic dolomitic 
limestone, quartzite, and gray micaceous phyllites of the metamorphic 
Paleozoic group; and they are in a short distance again succeeded by a 
broad zone of monotonous mica schist, amphibole schist, and gneiss, 
penetrated by eruptives. The main range of the Ts'in-ling-shan is thus 
reached and is found to consist of the supposed Archean schists and huge 
intrusions of granite, which extend to the northern margin. 

This zone of gneiss-granite, gneiss, amphibole schist, mica schist, 
phyllite, and crystalline limestones, intruded by massive coarse-grained 
granite, corresponds in strike with the Fu-niu-shanf (described in a pre- 
ceding paragraph), and the petrographic characters of the rocks are sim- 
ilar to those of that range. The presumption is strong that the area is 
one of pre-Sinian schists and intrusives. They have not, however, been 
observed in unconformable relation beneath the Paleozoics, and their pre- 
Sinian age can not be considered established, in view of the fact that post- 
Paleozoic metamorphism and intrusion is general elsewhere in the region. 
Nevertheless, the weight of evidence is in favor of their antiquity, and if 
it be accepted we must regard the northeastern portion of the Ts'in-ling- 
shan as consisting of Proterozoic and Archean rocks. As we did not cross 
any western continuation of the ancient gneisses and granites in longitude 
108 30', the zone does not extend westward along the face of the range, as 

*Reise des Graf en Szechenyi in Ostasien, vol. i, p. 448 et seq. 
t Ibid., vol. I, p. 446. 



CENTRAL TS'lN-MNG-SHAN. 1 7 

it was supposed to. It apparently runs to a point west of Si-an-fu, about 
longitude 109 , and is a triangular area bounded on the southwest by 
metamorphosed Paleozoics and granites intruded into them. 

The next section toward the west, across the Ts'in-ling-shan, is that 
observed by the expedition of 1904-05, between Ch6u-chi'-hien and Shi- 
ts'iian-hten, in longitude 108 30' E. It lies not more than 65 miles, 100 
kilometers, west of L6czy's eastern route and 80 miles, 125 kilometers, east 
of von Richthofen's. 

In approaching the Ts'in-ling-shan from the Wei valley, in longitude 
108 15', from Chou-chi-hi6n, we expected to find the front of the range 
composed of granite, as shown by von Richthofen. Instead, the foothills 
and northern slopes consist of green schists, prevailingly chloritic, in which 
occur thin beds of quartzite and highly siliceous marble. These rocks dip 
toward the north at their northern margin, but a short distance south dip 
steeply southward. They maintain a uniform southern dip of bedding 
and schistosity for 5.5 miles to their southern limit at Liu-yii6-ho, where 
they are succeeded by white quartzite and massive gray limestone, folded 
in a syncline. The contact was not observed, but a coarse conglomerate 
of quartz, quartzite, and granite pebbles in a reddish or dark purple matrix 
is supposed to be the lowest stratum overlying the schists. It occurred in 
large masses in a brook, which flowed along and near the contact. These 
occurrences very closely resemble the relations observed by von Richt- 
hofen, who describes similar rocks in the statement quoted below. We 
agree with him entirely as to the petrographic likeness between the green 
schists of these sections and those of the Wu-t'ai system of Shan-si. Their 
position beneath a distinct series, which can not be younger than Paleozoic 
and from which they appear to be separated by a marked unconformity, 
is that of pre-Sinian terranes. 

Von Richthofen's description of the rocks which he assigns provision- 
ally to pre-Sinian series, can not be better stated than in his own words.* 
After describing the general aspect of the northern slope of the Ts'in-ling- 
shan as it rises from the plain of the Wei, he says, with reference to the 
Archean zone : 

The first rock seen in place near Yi-monn is granite, in part of medium grain, in part 
very coarse, a mixture of red orthoclase, some white plagioclase, quartz, and black mica. 
Here and there occurs a thinly laminated mica gneiss, which occasionally goes over into 
hornblende and chlorite gneiss. It is everywhere penetrated by granite. I saw no other 
rocks during this day. Typical gneiss and typical eruptive granite (with the exception of 
gneiss-granite) predominate probably in the entire width of the northern zone of the moun- 
tain range, for in the alluvial cones along the northern base, west of Kwei-tschonn, I saw 
only these rocks, which were there developed in great variety. 



*Cbina, vol. u, pp. 563 and 565 



18 RESEARCH IN CHINA. 

He describes the probable Wu-t'ai rocks thus: 

South of Twi-tsze-shang, gneiss and granite give way to a series of rocks which are 
characterized by green color, and when the component minerals are macroscopically recog- 
nizable consist of abundant hornblende or chlorite, or of both minerals, and exhibit great 
petrographic variety. Predominant are rocks composed of reddish feldspar, blackish 
green hornblende, and dark scales of chlorite. The last often occurs in irregular, some- 
times sharply fringed spots, with hornblende, which lie in a ground-mass composed essen- 
tially of feldspar. The chlorite then occurs next to the hornblende in such manner that one 
is inclined to consider it an alteration product of the latter. Dikes of granite, pegmatite, 
and quartz are common, especially in the northern zone. With reference to the arrange- 
ment of the constituents, as well as with regard to their distinct separation, the rocks vary 
greatly. Occasionally they are massive without recognizable parallel structure, and they 
then have in some places the character of serpentine, the feldspar being subordinate. 
More often the magnesium minerals are arranged in parallel surfaces, sometimes only 
partially, as is the case with mica in gneiss-granite; otherwise, however, so regularly that 
more or less nearly perfect hornblende and chlorite schists are produced. 

With the first steps on this formation I was reminded of the Wu-t'ai schists of northern 
Shan-si. Shortly there followed the typical members of that formation, as a very thick 
sequence of green, partially schistose rocks, in which none of the constituent minerals are 
macroscopically recognizable. The entire system of schists has, as a whole as well as in 
its members, the constant strike of west 12 north, east 12 south. The dip is uniformly 
south, mostly at an angle of 50 to 70 , occasionally less steep. * * * 

Before reaching Tsau-liang-yi other rocks are seen in great numbers in float from the 
eastern ravines. Predominant among them are dense, quartzitic rocks, whose fracture 
planes gleam with innumerable little feldspar crystals. These are probably altered clayey 
sandstone. Therewith occur conglomerates of rounded quartz, in a matrix which partly 
corresponds to the above-described rock, is partly purely quartzitic, and has a reddish to 
dark- violet color. As I was unable to find these rocks in place I can not say whether they 
correspond to the sandstones and conglomerates which occur in the lower part of the 
Wu-t'ai formation south of the temples of Wu-t'ai-shan, or whether they belong to the 
coal-bearing strata which are presently to be described. 

It will be observed that the pre-Sinian rocks are more extensively 
developed in the western section seen by von Richthofen than in the one 
observed by our expedition. We did not find the zone which is described 
by him as Archean gneiss and granite, and the belt of Wu-t'ai schists is 
but 5.5 miles, 9 kilometers, wide, whereas that in his section is 20 miles, 32 
kilometers, across. There is, indeed, little reason to suppose that the two 
occurrences are one and the same zone. The strike in von Rich thof en's 
section, east 12 south, if extended, carries the belt which he saw at least 
12.5 miles, 20 kilometers, south of that which we observed. This direction 
appears to be the trend of axes in the range, and it is probable that there 
are subparallel belts on distinct folds. If so, the eastern zone, extended 
northwestward, lies beneath the Wei valley, and the western, extended 
southeastward, ends before it reaches our route. We crossed an anticline 
in Paleozoic strata about in its line of strike. 



WESTERN TS'lN-UNG-SHAN. 19 

L6czy, whose observations of the eastern Ts'in-ling-shan have already 
been described, recrossed the range on the borders of Tibet, 65 miles, 100 
kilometers, west of von Rich thof en's route. Obrutchov followed the same 
way southward from "Hoj-shien" to "Quan-juon-shien," and returned 
northward by a route that diverges to the west and leads over Min-ch6u to 
Lan-ch6u-fu. The two geologists agree in describing the structure as that 
of close folding, involving overturned folds and overthrusts. They both 
observed more or less metamorphosed Paleozoic strata, which make up 
the great mass of the range, and among which Silurian, Devonian, and 
Carboniferous horizons are distinguished by fossils.* They also noted 
metamorphic schists of uncertain age, which are doubtfully assigned to the 
1 ' Archean' ' by L6czy , and by Obrutchov are distinguished from the Paleo- 
zoics under the general term of " metamorphic schists.' ' 

The section in which the " Archean ? M rocks are most prominent lies 
between "Lo-jan-shien" (Lo-yan-hi£n) and "Tschau-tjen" (Chau-tten) in 
longitude 106 20', between latitude 32 30' and 33 30' north. It is in the 
strike of a wide belt observed by von Richthofen, 45 miles, 70 kilometers, 
further east, which on the basis of the general stratigraphic sequence was 
classed by him as of Paleozoic age; and 80 miles, 125 kilometers, still 
further east, near Ssi-m6u-ti, we crossed gneisses, schist, and marble, which 
are intruded by large granite masses and which we also regard as meta- 
morphosed Paleozoics.f 

In the particular section of the western Ts'in-ling-shan under discus- 
sion, between Lo-yan-hi£n and Chau-tten, L6czy mentions the occurrence 
of crystalline schists, gneiss, and phyllite, and crystalline limestone, which 
Ke in isoclinal folds and are intruded by large bodies of diorite. He dis- 
tinguishes argillites, chloritic schists, and epidotic schists, as well as partly 
metamorphosed Paleozoic strata, from underlying gneisses, with which they 
are, however, folded. And he cites occurrences of fossiliferous Devonian 
and Carboniferous strata in nearby localities. The sections which he has 
drawn showt that the rocks which, on account of petrographic likeness, 
he has classed together, occupy a variety of positions with reference to those 
whose age is more surely established. The schists under discussion are 
indicated by a red tint and blue dashes. In section 2, profile plate 2, 
north of Lo-yan-hten, they appear overlying less highly metamorphosed 
"Wu-t'ai?" schists on one side and "early Paleozoic limestone" on the 
other, in a syncline; south of Lo-yan-hi&i, in the "Pej-ho-scha," they under- 
lie "Silurian" strata and rest upon granite. Still further south, beyond 

♦Reise des Grafen Szechenyi in Ostasien, vol. 1, pp. 422-439, plates 11 and vi. La Face de la Terre, 
Suess, vol. in, pp. 270-271, fig. 35. 
tVol. 1, pp. 308-310. 
JReise des Grafen Szechenyi, vol. 1, pp. 465 and 428, plate 11. 



20 RESEARCH IN CHINA. 

the broad zone of granite near "Jam-pa-quan," they appear to be intruded 
by granite dikes, and are folded in such a way as to constitute anticlines 
between which less highly metamorphosed strata, assigned to the Paleo- 
zoic, appear in synclines. 

From the observations of Obrutchov, L6czy, von Richthofen, and 
ourselves, in four parallel sections across the central and western Ts'in-ling- 
shan, it thus becomes apparent that the geologic structure involves several 
complex factors. There are metamorphic rocks, some of which are probably 
pre-Cambrian, and among them may be representatives of the basement 
gneisses as well as of the Proterozoic metamorphosed series. There are 
other metamorphic rocks of Paleozoic and probably also of early Mesozoic 
age, which vary in degree of metamorphism according to the intensity of 
action incident to local folding and intrusion. And there are areas of 
Paleozoic strata which exhibit little or no effect of metamorphism. These 
various masses are closely folded, overturned, and overthrust, producing 
relations as complex as some of Alpine structure. 

We may conclude that the occurrence of pre-Sinian rocks in the western 
Ts'in-ling-shan is highly probable. Where such rocks are known in the 
central Ts'in-ling-shan, they are chloritic schists with thin beds of quartz- 
ite and marble, very closely resembling the strata of the Si-t'ai group of 
the typical Wu-t'ai district. 

ANCIENT METAMORPHIC ROCKS BEYOND CHINA. 

Under this heading I propose to consider the relations of certain rocks 
which are variously classified as Archean, Wu-t'ai, Sinian, early Paleozoic, 
and Silurian, by observers in Tibet, Indo-China, and India. 

In Tibet they constitute the unfossiliferous pre-Devonian series of the 
great Nan-shan mountain system, and have been observed by I*6czy in 
his journey along the northern base of the Nan-shan range, from Lan- 
ch6u-f u to Sii-ch6u and return ; and by Obrutchov in his far more extended 
journeys across southern Mongolia and back and forth among the several 
great ranges of the Nan-shan. 

Under the heading crystalline schists,* L6czy says : 

The Archean complex of gneisses, mica schists, and phyllites plays a subordinate 
rdle in those parts of the middle Kuen-lung chain which we traversed. In none of the 
mountains which we crossed was I able to distinguish a crystalline axis. 

He then discusses at some length various occurrences of crystalline 
schists, having in mind chiefly their eccentric position in the individual 
ranges in which they occur, but gives little information concerning their 

*Reisc <to Grafcn Sz^cbenyi, vol. i, p. 643. 



OBRUTCHOV, NAN-SHAN RANGE. 21 

geological relations. As constituent rocks of the Archean he repeatedly 
mentions gneiss, mica schists, amphibole schists, crystalline limestone, 
mica phyllite, gneiss-granite, and biotite-muscovite granite. 

Referring apparently to the same series of ancient crystalline rocks, 
Obrutchov frequently employs the terms ' ' metamorphic sandstones and 
schists." With reference to the Barun Ula range,* he says: 

The axial part of the range is chiefly composed of red and green Archean gneisses 
dipping steeply inward on both slopes, that is, forming a remnant of an ancient syncline. 

In various sections of the different constituent ranges of the Nan- 
shan system which he crossed, for example in that of the Potanin range,f 
he distinguishes a group composed of gneisses, quartzites, micaceous 
schists, and intrusive granite, from semicrystalline schists, quartzites, and 
limestones. Describing a section across the Richthofen range, he says : 

On the southern slope we see a thick series of supra-Carboniferous deposits, forming 
one of the southern ridges, the divide of the range. They strike north-northwest diago- 
nally across the range and dip steeply inward on both sides. Below the peak Yang-kou-er 
appear more ancient formations, namely gray sandstones and shales, slightly metamor- 
phosed, which I consider early Paleozoic. They do not closely resemble the ordinary 
metamorphic sandstone and schists of the Nan-shan and other parts of central Asia where 
I have seen them. Perhaps they are Silurian, perhaps still older. 

It is much to be regretted that Obrutchov's third volume, in which 
he proposed to interpret the notes published in the two now available, 
has not appeared. As they stand the voluminous accounts of his observa- 
tions offer little more than detached petrographic descriptions, from which 
geologic relations can hardly be deduced. 

L6czy distinguishes a system which he describes under the name 
Nan-shan sandstone, and which, after having studied von Rich thof en's 
second volume, he referred provisionally to the Wu-t'ai and Sinian systems, 
but he did so only with the reservation that the correlation is suggested, 
but not established, by the likeness in lithologic character and degree of 
metamorphism exhibited by the rocks of the several systems. Regarding 
the Nan-shan sandstone, he states that it consists chiefly of gray-green 
sandstones and clay slates, which are frequently traversed by distinct 
cleavage or schistosity and which are barren of fossils, except for occasional 
indistinct impressions, that may possibly be ascribed to fucoids. From 
the various sections and descriptions given in his chapter on the northern 
slope of the Nan-shan range, J it appears that the Nan-shan sandstone is 
very intimately folded and is intruded by large masses of granite. 

* Central Asia, North China, and the Nan-shan. Obrutchov, vol. u, p. 79 (in Russian). 

t/Mtf., vol. u, p. 115. 

I Rose des Grafen Sz&henyi, voL 1, pp. 532-559. 



22 RESEARCH IN CHINA. 

Another series described by L6czy, which belongs in this category, is 
that which he designates early Paleozoic limestones. He says :* 

At several points in the range of the Nan-shan I found light-colored, dense, half- 
crystalline, sometimes siliceous, dolomitic limestones. Everywhere the limestones occur 
in moderately thick strata, conformably bedded with the Nan-shan sandstone, either inter- 
bedded or in the form of "Klippen." In none of these limestones could I find fossils, even 
in numerous thin sections. The investigations of Dr. Konrad Schwager of the material 
sent to him likewise yielded a negative result. Lines which might suggest bivalves, a 
spheroidal inclusion with a tangled, reticulated character, and a globulitic structure, occa- 
sionally suggest an organic origin. 

At the time that L6czy and Obrutchov wrote their descriptions they 
could compare the formations which they had observed wily with the 
Archean, the Wu-t'ai or Huronian, and the Sinian. According to von 
Richthofen's definition, the latter comprised strata conformably under- 
lying the Cambrian, which might therefore be considered the most ancient 
Paleozoic deposits. In distinguishing the Nan-k'ou or Hu-t'o system as a 
pre-Cambrian series, separated from the fossiliferous beds by an uncon- 
formity and characterized by highly siliceous limestones and slight meta- 
morphism, we have found a series which closely resembles the rocks which 
L6czy designates early Paleozoic. As the limestones to which he thus 
refers are interbedded with the Nan-shan sandstone, some part of that 
system is also probably to be referred to the Nan-k'ou (Hu-t'o) terrane. 

Among the more highly altered metamorphic schists, quartzites, 
and crystalline limestones, there may probably be found the representa- 
tives of the Wu-t'ai system. It would not be surprising if outcrops of 
these ancient formations should be found to lie in one or more rudely con- 
centric arcs corresponding to the strike of the mountain ranges, which 
extend from the type locality, the Wu-t'ai-shan in northern Shan-si, through 
southern Shan-si and across Shen-si and Kan-su to the Nan-shan in Tibet. 
This is the outline of the continental region during the succeeding Sinian 
age, and it would be in accord with the general laws of relation between 
continental structure and mountain trends that representatives of the 
Wu-t'ai system should be found at intervals along this arc. 

In his southward journey from the northern Tibetan regions where the 
Nan-shan sandstone is typically developed, through western Yun-nan to 
Burmah, L6czy observed formations which he correlates with it.f They 
occur chiefly between Ta-tsi6n-lu and Ba-t'ang in the outer ranges of the 

♦Reise des Graf en Sz&henyi, vol. i, p. 651. 
f Ibid., vol. I, p. 724. 



ANCIENT SCHISTS, INDO-CHINA. 23 

Alps of eastern Tibet. He describes the rocks as monotonous clayey 
sandstone, of gray and dark colors, associated with clay schists and also 
with amphibolite and chlorite schists. The presence of the latter leads 
him to correlate the series with the Wu-t'ai. Semicrystalline limestones 
occur beneath the sandstones, the strata being extensively intruded by 
granite. 

Throughout much of Indo-China there occur ancient schists which are 
described by Fuchs and Saladin,* who distinguish two varieties, the one 
greenish, siliceous, hard, and compact, apparently the upper part of the 
terrane; and the other a gray, lustrous schist. These metamorphic rocks 
are associated with granite, which, as we may infer from the language of 
the authors, is probably intrusive. The petrographic description is suf- 
ficiently close to that of L6czy to suggest that these metamorphic strata 
correspond with the supposed Nan-shan sandstone occurring between the 
Ta-tsi6i-lu and Ba-t'ang, especially as the mountain ranges and structural 
features are continuous. The schists are, however, classed by Fuchs and 
Saladin as possibly Silurian (probably in the sense of early Paleozoic) as 
they underlie fossiliferous Devonian schists and sandstones; but the strati- 
graphic relations have not been worked out and it is not clear how old the 
pre-Devonian rocks may be. In a recent letter from M. Emm. de Mar- 
gerie my attention is called to the occurrence of extensive and massive 
conglomerates which may represent the lower Cambrian or pre-Cambrian 
glacial deposits in this region. 

Westward from Yiin-nan and Burmah in the Himalayas occur ancient 
rocks which were described as an older granite-gneiss and a younger series 
of schists (the Vaikrita systemf). HaydenJ states that the granite-gneiss 
is intrusive in Cambrian and Permian strata, and that certain schists 
assigned to the Vaikrita system are altered Cambrian slates and quartzites. 
In the Peninsula region of India gneisses have been distinguished as older 
and younger, but without sufficient basis in observed relations, according 
to Oldham. § No distinctly sedimentary pre-Cambrian rocks are known 
there. 

Thus we are not as yet able definitely to distinguish metamorphic 
Proterozoic rocks in south China or India in such a way as to draw a 
parallel with the Wu-t'ai schists. 

* Explorations des Gttes de Combustibles de l'lndo-Chine, Annates des Mines, 8 sex., Mem. 2, p. 205. 
tGriesbach: Geology of the Central Himalayas, India Geological Survey Memoirs, xxni, p. 40. 
t Geology of Spiti, India Geological Survey Memoirs, xxxvi, pt. 1, p. 8. 
§ Manual of Geology of India, page 23. 




24 RESEARCH IN CHINA. 



PRE-SIN1AN DIASTROPHISM.* 

Diastrophism is a phenomenon which finds expression in the oldest 
rocks as well as in the youngest mountains of all continents, and of this 
general fact Asia is the most striking illustration which the earth presents. 
Large areas exhibit rocks which have been intensely deformed and are 
among the most ancient known ; and the greatest mountain chains challenge 
credulity by the evidence of their extreme youth. The earlier diastrophic 
movements escape us in the mists of unrecorded ages of earth-history; we 
take up the observation only where the facts become partly intelligible; 
but from that remote time to the present we find a connected series of 
events. 

Suess describes these facts and draws the conclusion that : 

The compressive force formerly acted throughout the entire expanse of the globe, 
whereas now it is localized in certain special regions, f 

An alternative view may be stated: namely, the widely distributed 
effects of schistosity are produced in masses that lie in a relatively deep- 
seated zone, where movement is somewhat uniformly distributed ; whereas, 
special regions of folding are peculiar to a relatively superficial zone, in 
which movement is localized and concentrated by special conditions of 
structure and resistance. That is to say, the distinction between widely 
distributed and localized structures is one of depths rather than of times. 
This view is stated more in detail in the final chapter of this volume. 
Applying it to the explanation of the general structure of the Archean, 
we may reason that the masses which that structure characterizes were 
deformed in a zone at such a depth that they were below any localized 
orogenic effects. That there were regions of special plication, even in the 
Archean is probable, but the superficial folded masses have been eroded. 

Gneisses and schists constitute the T'ai-shan complex of China and 
also the corresponding rocks described by many observers in Siberia, central 
Asia, India, and Indo-China, and designated "older Archean." They are 
everywhere fundamental rocks; their constitution is very complex; they 
consist of minerals resulting from extreme metamorphism under great 
pressure; and their larger structure exhibits repeated intrusions, often 

♦Following Powell and Gilbert (U. S. G S. Monograph i, pp. 3-340) I shall use the term diastrophism 
to denote all the processes of deformation of the earth's crust, and shall distinguish between orogenic move- 
ments, which result in the commonly observed phenomena of mountain ranges and mountain structure, 
and epeirogenic movements, which are expressed in the elevation or depression of broad areas and are 
recorded in eroded surfaces or accumulated sediments. The distinction is one which has found little, 
if any, recognition in the literature relating to Asia, but which is fundamental and clearly recognizable in 
the geologic facts. 

tLa Face de la Terre, vol. ni, p. 7. 



UBITUNIBN OF THB ARCHfiAN. 25: 

along parallel planes. It is commonly recognized that they acquired these 
characters when deeply buried beneath masses, which subsequently were 
eroded in consequence of exposure above sea-level. 

To pursue this thought would lead too far afield in the direction of 
theory. Adhering to the facts, we may consider the leitlinien, or axial 
trends, of the Archean in Asia as developed by Suess.* They maintain 
two principal courses, the one known as the Saian direction striking east- 
southeast or southeast; and the other, the Baikal direction, east-northeast. 
Trends having these bearings meet south of Irkutsk, where they were first 
distinguished by Tchersky,f and there inclose on the south the amphi- 
theater of Irkutsk. By assembling the geologic observations for all northern 
Asia, Suess has traced these axial trends and shown that they characterize 
an immense area of eastern and western Siberia. The peripheral ranges 
extend from the island of Sakhalin across the Amur into northern Mongo- 
lia, in the Baikal trend, and thence in the Saian direction through the Saian 
mountains to the Ob. This structure is not only of vast extent; it is also 
fundamental, as well through its antiquity as through its nucleal position. 
About it are arranged the other structures of Asia. They are pendant from 
it, as Suess happily says, like garlands. 

Succeeding the Archean, in the sense given that term in these volumes, 
the next oldest rocks of which we have definite knowledge are the Wu-t'ai 
schists of northern Shan-si. They are early Proterozoic. They probably 
are not younger than many terranes classed as Archean in the broader 
sense of that term commonly employed by writers on Asiatic geology, for 
similar strata have not, as a rule, been sharply distinguished from the basal 
gneisses. 

The Wu-t'ai schists are distinct sediments, which represent familiar 
conditions of erosion in a sequence that is generally recognized among 
later deposits. Unfortunately our interpretation is in a measure balked 
by uncertainty of the exact stratigraphic succession and ignorance of the 
former extent and distribution; but I proceed on the basis of pur present 
understanding. 

According to that, the lower Wu-t'ai strata are heterogeneous, quartz- 
ose and clayey in the lower part, more argillaceous in the middle, calcare- 
ous above; and this lower series is unconformably succeeded by a great 
thickness of shale which carries a basal conglomerate of large quartz and 
quartzite pebbles. Regarded as products of erosion the strata have a 
perfectly normal sequence, which corresponds to a complete erosion cycle 

♦La Pace de la Terre, vol. m, chapter m, Le Falte Primitif. Summary on page 138. 
fl. D. Tchersky. Sur la tectonique des montagnes de la Siberie Orientate. Trav. Soc. des Natura- 
listes, St. Petersburg, xvii, No. 2, 1886. Proces-verb. pp. 52-58. 




26 R8S3ARCH IN CHINA. 

and subsequent prolonged continental phase, or marine transgression. The 
latter is more probable, but we can not on present evidence exclude the 
possibility that the upper Wu-t'ai strata accumulated subaerially on a low- 
lying land. Confining our attention for the moment to the lower series, 
which ranges from quartzose argillaceous to calcareous, we recognize a suc- 
cession of rocks which, though much older, resemble the Sinian (Cambro- 
Ordovician) terrane. At the base are the weathered, oxidized products of 
subaerial rock decay, such as, in consequence of exposure above the plane 
of gradation, are transported by streams and delivered to the sea. Toward 
the top are the finer, finally chiefly calcareous sediments, which result from 
the topographic and climatic conditions that follow from prolonged fixed 
relations of land and sea. The unconformity indicates an interruption of 
those relations which, if the overlap of the next later strata on the Archean 
be as great as we suppose, was a very notable interruption. The upper 
series represents ultimately renewed erosion, transportation, and deposition. 
The Wu-t'ai deposits are several thousand feet thick. They are at least 
equal to the Cambro-Ordovician in duration of time and altogether may 
equal most of the Paleozoic. The nature and volume and sequence of 
sediments correspond with those which represent epeirogenic movements 
and static conditions of later periods; they evidently indicate equivalent 
movements and conditions for those early times. 

The Wu-t'ai strata were folded and intruded by igneous rocks, and the 
whole mass was rendered schistose before the next succeeding formation 
was laid down in the typical district. The igneous rocks became gneisses ; 
the heterogeneous strata became biotite, muscovite, and chlorite schists; 
and the limestones changed to marbles, with the development of garnet, 
staurolite, and other minerals from the shaly beds. Metamorphism was 
preceded by or associated with folding and thrusting into isoclinal struc- 
tures. The phenomena compare in intensity and volume of rocks affected 
with the effects shown by the Paleozoics of the Han region, China, or of 
the Sierra Nevada, California, as a result of deformation during the Permo- 
Mesozoic. 

Thus we see that the Wu-t'ai region passed through an epoch of intense 
orogenic activity at the close of the Wu-t'ai period of the Proterozoic era. 

In other districts than that of the Wu-t'ai-shan, Shan-si, where strata 
are identified by lithologic character as being probably of Wu-t'ai age, the 
structural facts are less well known. In the Ts'in-ling-shan, Shen-si, chlo- 
ritic schists with some limestone and quartzite occur unconformably beneath 
Paleozoic strata, from which they are markedly distinguished by greater 
metamorphism. The suggested events of deposition and orogenic disturb- 
ance are comparable in time and character with those of the typical region. 



ANTIQUITY OF MOUNTAIN SITES. 2^ 

Regarding the great Kuen-lung system of Central Asia, the available 
data clearly distinguish highly metamorphosed sediments beneath Devonian 
or pre-Devonian strata. They appear to fall into two groups, of which one 
consists of schists like the Wu-t'ai schists, rocks of the other group being 
less altered; and the facts indicate a sequence of activities which resemble 
those of Wu-t'ai time. 

Thus in an arc which extends from the Wu-t'ai-shan in Shan-si around 
the southeastern and southern margins of the Mongolian plateau, there 
may be traced evidence of a very ancient mountain movement or group of 
movements. The axial trends of the early structures correspond in a 
degree, though not exactly, with the existing ranges, and this coincidence 
forms a reasonable basis for the view that certain conditions, possibly 
mechanical, have controlled and still control the courses of mountain 
chains. The coincidence does not demonstrate the continued existence 
of the Wu-t'ai or Kuen-lung ranges as mountainous elevations from early 
Proterozoic time to the present; in view of the stratigraphic evidence that 
Sinian lands were low, or of the physiographic evidence that the present 
mountains have grown up largely since the Tertiary, such a hypothesis is 
untenable. Nevertheless, it is one which was commonly accepted thirty 
or forty years ago. Von Richthofen regarded the Kuen-lung line as a great 
divide established in a very early period,* and describes the Ho-shanf as 
a monument of the oldest time, which formed a long island in the Carbonif- 
erous sea. King's views of the antiquity of mountain heights of the United 
States are clearly expressed in the volume on the systematic geology of 
the Fortieth Parallel. The effectiveness of erosion and the significance of 
strata as records of highland or lowland conditions have since received 
more adequate recognition. Beginning with Powell's conception of a base- 
level and the demonstration that the Appalachian folds had been planed, J 
the generalization has been developed that existing heights are nearly all 
post-Cretaceous and largely post-Miocene. But at the same time the view 
has been strengthened that zones of mountain growth are so conditioned 
that repeated elevations occur on the same sites with similar trends, though 
at widely separated intervals. In the latter sense the Wu-t'ai and Kuen- 
lung axes of mountain growth are very ancient, one may say primeval, 
features of Asia. 

Traces of the mid-Proterozoic epoch of orogeny are found in Liau-tung 
and Shan-tung, the eastern mountain provinces, in meager occurrences of 
pre-Sinian sediments, which are so metamorphosed as to be compared to the 

* China, vol. 11, pp. 647-648 and 709. 

t/wa., p. 457. 

% W. M. Davis, Rivers and Valleys of Pennsylvania, Nat. Geog. Mag., vol. 1, p. 185, 1889. 




28 RESEARCH IN CHINA. 

Wu-t'ai schists. Von Richthofen enumerates them* and nothing has been 
added to his account except Blackwelder's notes on the Ta-ku-shan quartz - 
ites. The facts do not suffice to fix any dates other than that one which 
preceded late Proterozoic. In the great lapse of earlier time there were in 
North America, and probably also in Asia, several cycles of erosion, sedi- 
mentation, and orogeny, and the correlation on lithologic likeness is incon- 
clusive. We believe the Wu-t'ai terranes to be divided by an unconformity , 
and similar divisions probably exist elsewhere. Hence we can not establish 
equivalency of the epoch of folding in Shan-tung with that which was so 
decided in the Wu-t'ai, but in view of the intensity of effects in both regions, 
a rough correlation has a presumption in its favor. 

The orogenic activity, which affected the Wu-t'ai rocks before any 
later beds known to us accumulated, divides the Proterozoic of China into 
two major periods. The earlier, the Wu-t'ai, links itself to the much 
older Archean; the later, the Hu-t'o or Nan-k'ou period, is like the early 
Paleozoic in general character. Whatever elevations resulted during the 
dividing epoch of orogenic activity, they did not survive to deliver sedi- 
ments to the Nan-k'ou seas. Except that they may be represented by 
rocks which are not yet separated from the late Proterozoic, we must sup- 
pose that the mid-Proterozoics were deposited beyond the confines of the 
continent or in the deep synclinoria which in pre-Tertiary time traversed it. 

Strata of the Hu-t'o system in the typical district succeed the Wu-t'ai 
after an interval represented by the profound orogenic activity described 
in the preceding paragraph. The sequence of sediments ranges from 
elastics of rather fine grain to carbonates; quartzites interbedded with 
greater thicknesses of slates pass by transition upward into cherty lime- 
stones. The total thickness is very roughly guessed at 5,000 feet, 1,500 
meters. The elastics are terrigenous deposits, probably of the littoral 
zone. The equivalent marine formations are the lower limestones of the 
Nan-k'ou formation, of which the upper part is probably identical with 
the limestone of the Hu-t'o system. The unconformity and succeeding 
strata mark a transgression upon a flat land, which was sufficiently warped 
to deliver to the coastal waters the sands and clays of residual and alluvial 
deposits. Off shore, at a distance of 50 miles, 80 kilometers, or less, lime- 
stone formed from the very inception of the transgression, and extended 
landward as the sea widened. Such is the record for North China. If we 
rightly correlate the Nan-shan sandstone, or that part of it which carries 
the "early Paleozoic" limestones of L6czy, with the Hu-t'o system, the 
evidence of similar shore conditions may be traced westward across Tibet. 

♦China, vol. II, p. 707. 



CLOSE OF THE PROTBROZOIC. 29 

I<ate Proterozoic strata are not known in Shan-tung, which seems 
to have formed an eastern shore of the strait in which the Nan-k'ou lime- 
stone was deposited. Nor have they been noted elsewhere in Asia outside 
of Tibet, unless some of the rocks of western Ytin-nan, which L6czy assigned 
to the Nan-shan terrane, prove to be of that age. 

In their typical occurrence in northern Shan-si, Hu-t'o strata are dis- 
cordantly overlain by the earliest Sinian (Cambrian) sediments. The older 
rocks were evidently folded and eroded to a peneplain, over which the 
Sinian sea transgressed. Where we observed the Sinian in relation to the 
Nan-k'ou limestone (at Nan-t'ang-mei, Chi-li) an unconformity is indicated 
by a basal conglomerate of chert.* A discordance of dip was not observed, 
but probably exists; yet the strata may be parallel. There are no other 
observations which enable us to determine the area affected by the post- 
Nan-k'ou pre-Sinian disturbance. The effects may be looked for through- 
out that littoral zone in which the type locality lies and which probably 
extends along the Kuen-lung system. The movement did not compare in 
intensity with that which closed the Wu-t'ai period; and even though it 
should ultimately be found to have affected an extensive belt, we can not 
assign to the epoch of deformation and consequent erosion a duration at 
all equivalent to that of mid-Proterozoic diastrophism. Nevertheless, 
it appears to mark a break in continental history equivalent to that at the 
base of the Cambrian in North America, and consequently to be properly 
regarded as the last episode of the pre-Cambrian, immediately antedating 
the Sinian transgression and the advent of that Lower Cambrian fauna 
which is abundantly preserved in the Sinian deposits. The limitation of 
the term Sinian to a Cambro-Ordovician system is discussed in the next 
chapter. 

Our present knowledge of pre-Cambrian diastrophism in eastern Asia 
may be summed up as follows: During very early times movements which 
are expressed in schistosity and metamorphism of the most ancient rocks 
occurred in a deep-seated zone. The superficial effects of the compressive 
movements are lost; that is, the fractured and simply folded rocks of that 
early time were eroded and the schists were exposed. The wide-spread 
occurrence of the Archean schists shows that epeirogenic movements were 
general. Of localized orogenic phenomena we have no direct evidence, 
yet we can not doubt that they also developed in a commensurate scale. 
The axial trends of Archean rocks are north-northeast (the Baikal direc- 
tion) and west-northwest (the Saian bearing). These meet south of the 
amphitheater of Irkutsk, and further south are connected by the trends 
which correspond with the Altai ranges of northern Mongolia, 

* Vol. I of this report, p. 131. 



30 RESEARCH IN CHINA. 

During the early Proterozoic a synclinorium developed on the site of 
the present Wu-t'ai-shan of northern Shan-si, and in it were deposited 
sediments which correspond in sequence with the progress of a cycle of 
erosion from youth to old age and subsequent marine transgression. These 
sediments were probably common to a zone which extends from the type 
locality northeast and southwest; in the latter direction it enters the 
Ts'in-Ung-shan and thence curves west to northwest across Tibet in the 
Kuen-lung system. The corresponding diastrophic movements were epei- 
rogenic, and they passed into a phase of quiescence such as has since 
repeatedly characterized such movements. It is probable that there was 
more than one epoch of erosion, at least one unconformity being recognized 
in the sedimentary series. 

At a period which may be described as mid-Proterozoic, the zone of 
early Proterozoic sediments was sharply and intensely deformed. The 
disturbance was apparently accompanied by granitic intrusions of large 
volume, which were then or afterward rendered schistose in common with 
the folded strata. The events were complex. The movements may be 
classed as orogenic, since they resulted in deformation of strata by folding 
and thrusting in an apparently well-defined zone. The strikes follow the 
Baikal direction, northeast-southwest in North China, change in the 
Ts'in-ling-shan to east-west and northwest, and extend to the Kuen-lung. 
They thus form an arc outside that of the Baikal-Saian curve, embrac- 
ing Mongolia, as was perceived by von Richthofen* and has been brought 
out by Suessf and others. This period of orogeny was for the provinces 
affected equally as important, apparently, as the intense orogenic disturb- 
ances which mark the Permo-Mesozoic period in Central Asia and the 
western United States. It was very possibly an incident of a period of 
diastrophic activity such as closed the Paleozoic. 

After a period of erosion, during which the altitudes that had resulted 
from the preceding activity were materially or completely reduced, but of 
which no sedimentary record is known, there followed a cycle characterized 
by the deposition of littoral sediments in the typical district of the Wu-t'ai- 
shan, and of marine limestones in a trough which traversed eastern China. 
Strata, which may be equivalent, occur in the Nan-shan range of northern 
Tibet. The deposits again correspond with the phases of an erosion cycle 
from youth to old age, and finally represent a transgression over a low 
continent . 

The last event of the Proterozoic (pre-Sinian) era was a movement 
which is recorded in folding of the latest pre-Cambrian sediments ; although 
possibly a local phenomenon of the littoral zone, so far as is yet known, it 

♦China, vol. u, pp. 635 el seq. t 647. 
fFacc dc la Tcrrc, vol. m. 



THE PLAIN O* TRANSGRESSION. 3 1 

occasions a decided unconformity of structure in the Wu-t'ai district and 
is represented by an erosion interval, even where there is no known dis- 
cordance of dip with the Sinian. It is consequently regarded as an interval 
of sufficient importance to distinguish the Hu-t'o or Nan-k'ou system of the 
Proterozoic era from the Sinian system of the Paleozoic era. 

PRRSINIAN UNCONFORMITY. 

The unconformity at the base of the Sinian system divides the Paleo- 
zoic from the pre-Cambrian. It is a break of the first magnitude, corre- 
sponding to a period of deformation and erosion, even where the underlying 
strata are the Ta-yang (Nan-k'ou) limestone of the late Proterozoic. More 
commonly the subjacent rocks are Archean and the hiatus embraces the 
much longer times which are in some localities represented by the two 
Proterozoic systems of strata and the sum of deformations and erosions 
they have undergone. 

The latest cycle of erosion with which the Proterozoic closed was very 
complete. The land surface was reduced to a nearly perfect plain, upon 
which the transgressing sea of Sinian time found few eminences to level. In 
this statement we agree with von Richthofen as regards the completeness 
of planation, but differ from him in assigning to erosion the greater part 
of the work accomplished. In accordance with the prevailing views of the 
time in which he wrote his second volume of China, he therein held that the 
major work of denudation was due to marine abrasion. He says: 

The first great occurrence after the episode of folding was an extensive abrasion, by 
far the most important which is to be demonstrated in the geological history of China. 
The complete difference between the tectonic movements which occurred before and after 
the period marked by this boundary suffices to show that a very long time interval lay 
between the happenings of the fifth and seventh phase, since a portion of the earth's crust 
which previously had been capable of intense internal movement was so stiffened that it 
thereafter only changed its level as a whole ; but we obtain a more definite idea of the great 
length of this sixth period when we consider that enormous mountain masses which covered 
continental areas were completely swept away. From the fact that formations whose 
thickness can be measured only by tens of thousands of feet occur in single troughs, we are 
obliged to draw the conclusion that these are relatively small roots of former folded moun- 
tain chains, which attained at least the height of the Alps, but then almost completely 
vanished. We have repeatedly referred to the breakers of an advancing sea, which trans- 
gressed over the land in consequence of simultaneous mechanical erosion and positive sub- 
sidence, as the one agent which is able to produce a level surface where there previously 
existed an extensive mountain range. However much assistance may be given by atmos- 
pheric influences and the running water of the mainland, this alone is competent to produce 
an almost even surface of great extent. That force is the only one which we may here 
postulate. The surf removed not only the folded masses of the ancient formations, but 
also attacked their foundation, the old gneiss, and developed a plane of abrasion which ex- 
tends across the remaining portions of the gneiss as well as over the synclines of the younger 



32 RESEARCH IN CHINA. 

Archean strata and the Korea granite, as is clearly proven by the uniform occurrence of 
the wide-spread covering of Sinian sediments. The surface was not, however, perfectly 
uniform, as the eroding force could not overcome the resistance of the hardest rock. The 
quartzites stand up in high reefs, as we have seen in Liau-tung at Sai-ma-ki and Ta-ku-shan. 
The Korea granite stands out occasionally in steep high bluffs, and yet in the immediate 
vicinity it occurs as the surface of a plain of abrasion on which Sinian strata lie in horizontal 
and undisturbed position. The irregularity of the action appears especially about the hard 
cores of gneiss in the mountains. We have seen how the layers of the principal mass of 
gneiss, which, around the Yellow Sea, strike north-northwest south-southeast and dip 
steeply, were involved in the thrust in the Sinian direction and thrown into disturbed 
positions which probably facilitated erosion, while near these deeply eroded and decom- 
posed masses wild ridges of unweathered gneiss stand up. We must consider them the 
massive cores which were not destroyed by the surf. They form the characteristic moun- 
tains of eastern Shan-tung and Liau-tung.* 

The view that notable elevations were cut away by the waves is not 
tenable in contradiction of the evidence of Sinian sediments. Where waves 
do attack bold coasts of gneiss, granite, schists, and quartzite, they spread 
coarse deposits of the obdurate rocks. Where large masses are rapidly 
leveled by subaerial erosion or marine abrasion, sediments of corresponding 
volume gather in some adjacent basin. The Sinian deposits do not repre- 
sent either of these conditions. They are neither coarse nor voluminous. 
They are frequently fine-grained calcareous shale or thin-bedded limestone 
at the very base. The mechanical sediment of the basal formation has the 
character of a fine alluvium and is of uniformly moderate thickness, 350 to 
500 feet, 105 to 150 meters. The material is red soil, particles of ferrugi- 
nous clay being thoroughly oxidized and grains of sand coated with ferric 
oxide. The plane of contact at the base is sharply defined, usually very 
even, not broken by abrupt hollows or decided projections, but swelling 
gently over rounded bosses of the harder rocks. Pebbles of the subjacent 
rocks are wanting in the basal deposits, as a rule, and where they occur are 
limited to very local accumulations. Beds of arkose have not been seen, nor 
even beds of clean sand such as waves usually spread. Thus none of the 
effects of violent breakers are present ; the evidence is that a gentler agent 
cleaned the surface of the ancient rocks. The facts support the view that 
the lowest strata of the Man-t'o formation were laid down in the shallows, 
lagoons, and flood-plains of a very low, flat coast, where weak waves, feeble 
shore currents, and rivers interacted. 

The smooth surface of the old rocks is one which has been swept clean, 
as by the wash of little waves or by the wear of a stream engaged in lateral 
corrasion. It is probable that a layer of saprolite was removed in the 
process. The material laid down on the bared rocks is usually mud, occa- 

■ 

♦China, vol. n, pp. 710-71 1. 



GENERAL PLANATION. 33 

sionally mingled with coarser stuff. In the special case of the Yung-ning 
sandstone of Liau-tung, it is cross-bedded like a stream deposit from swift 
and variable currents; usually it is evenly stratified after the manner of 
deposits from quiet waters or on flood-plains. It is barren of fossils up to 
100 feet, 30 meters, above the base, but above that horizon marine forms 
are evident. 

Hence it is reasonable to infer that the zone of unconformity, compris- 
ing the immediately subjacent rocks, the contact, and the directly super- 
jacent strata, represents a coastal plain reduced through erosion and lateral 
corrasion by streams to an even surface; covered during an early stage of 
subsidence relatively to sea-level by alluvium, and buried beneath fine, ill- 
assorted shore deposits of a shallow, rippling, advancing sea. Where the 
waves removed the alluvium the marine strata are among the lowest; 
where they did not, the bottom layers are of fluviatile origin. 

It is possible that such a coastal plain should be diversified by an 
occasional hill of resistant rock, and hills of that kind may still survive if 
preserved through burial in sediment. Where the strata have in a recent 
geologic epoch been eroded from about them, they may again appear as 
prominent features of the landscape. Such was von Richthofen's view 
regarding the quartzite ridge of Ta-ku-shan and others like it. While grant- 
ing the possibility of individual cases occurring, we do not agree to the 
statement of the final sentence in the preceding quotation : ' ' They constitute 
the characteristic mountains of Shan-tung and Liau-tung." We consider 
the present relief of those peninsulas to be a relatively very modern phenom- 
enon, and hold that resurrected hills of the early Sinian epoch are few. No 
case of the sort came under our observation. 

The preceding statements apply to the unconformity at the base of 
the Sinian, wherever we saw it: in Shan-tung, Liau-tung, Shan-si, and 
Hu-pei*. Its character as a plane is uniform over a stretch of a thousand 
miles, representing several hundred thousand square miles of contact. It 
is a feature of southeastern Asia, from latitude 30 to 42 north and longi- 
tude 108 to 124 east. 

Near Ta-tung-fu in northern Shan-si, von Richthofen observed an 
occurrence of characteristic Sinian limestones, having at the base red, clayey, 
and calcareous thin-bedded deposits, which rest unconformably on gneiss. 
He remarks that the " Untersinisch," i. e. f the Nan-k'ou limestones, are here 
wanting. The occurrence is one of overlap of the Cambrian strata, to 
which we restrict the term Sinian, beyond the pre-Cambrian, Nan-k'ou, 
limestones or their littoral equivalents onto a much older pre-Cambrian 
(Archean?) gneiss.* 

*China, vol n, p. 358* 



34 RESEARCH IN CHINA. 

A similar plane of unconformity presumably characterizes northern 
Siberia, where the great plateau of flat Paleozoic strata north of Irkutsk 
stretches from the Lena to the zone of folds adjacent to the Archean areas 
along the Jenissei'. The base of the Paleozoic is there Lower Cambrian, 
and the surface beneath it is of the same prolonged cycle as that in south- 
western Asia. 

An unconformity comparable with that at the base of the Cambrian 
system occurs throughout Central Asia also, but the superjacent strata are 
probably Devonian or Silurian. The surface developed on the pre-Cambrian 
rocks is therefore younger than the Sinian, and there is room to question 
what features existed in CentraV Asia during the Sinian period. It is prob- 
able that the epicontinental sea did not spread over the entire region where 
the corresponding strata are now absent, although it no doubt covered some 
part. Whatever land area was exposed at any stage of the advance and 
retreat of the waters was then being eroded and furnished the sediment of 
the Sinian strata, which, had there been any considerable height of land, 
would consist of shaly and sandy deposits. They are, however, limestone, 
and it is a fair inference that practically all Asia, draining to the Cambro- 
Ordovician sea, was low and featureless. 

The fact that Asia at the opening of the Paleozoic era was a featureless 
continent has important bearings. It limits the antiquity of mountain 
ranges, some of which have been discussed by eminent writers as of pre- 
Cambrian date, as elevations which have survived since that remote time; 
and it affords a basis of inference regarding a cycle of inactivity, which was 
common to other continents as well. 





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CHAPTER IH— EARLY PALEOZOIC 



SINIAN SYSTEM (CAMBROORDOVICIAN). 

The name and its application. — Sinian was first applied by Pumpelly 
to the prevailing structural axes of eastern Asia, which trend northeast and 
southwest.* It was adopted by von Richthofen to designate a series of 
conformable strata which exhibit folds having the Sinian direction. They 
are characterized in part by Cambrian fossils, but were believed by him to 
extend downward below the base of the Cambrian, and at the top to include 
part of the Ordovician. The term is here used to designate the Cambrian 
and Ordovician strata to which he applied it, but those limestones which 
underlie the lowest fossiliferous Cambrian are excluded, after conference 
and agreement with von Richthofen himself. 

The problem which confronts us in determining the base of the Sinian 
is inherent in the more or less local nature of an unconformity. Each un- 
conformity is somewhere represented by continuous, conformable deposits, 
and the area of unconformity is bounded by areas of conformity. When 
we pass from one to the other there is difficulty in dividing the con- 
tinuous series of strata at a plane corresponding to that indicated by the 
discontinuity in the neighboring series. This condition exists at the base 
of the Cambrian in certain localities in the United States, where the lowest 
fossiliferous Cambrian strata are conformably underlain by great thick- 
nesses of sediments, that accumulated in the depressions from which the 
Cambro-Ordovician epicontinental sea expanded. Such sediments are by 
some regarded as pre-Cambrian, by some as the downward extension of 
the Cambrian. There is no difference of opinion regarding the base in 
sections where the unconformity intervenes, as is commonly the case. 

In China there is usually an unconformity at the base of the distinc- 
tive red formation of the Sinian, and Cambrian fossils occur within ioo feet 
above the contact. Von Richthofen observed this conspicuous break, and 
we also obtained evidence of it in every section in which we saw the appro- 
priate contact. But there are sections such as that of the Nan-k'ou pass, 
northwest of Peking, in which the unconformity was not noted by von Richt- 
hofen and may not exist. The strata there below the Cambrian are siliceous 
limestone, equivalent to that which is apparently unconformable beneath 

♦Smithsonian Contributions to Knowledge, vol. xv, Geological Researches in China, Mongolia, and 
Japan, p. 67. Sinian from Sinim, the name applied to China in the earliest mention made of that 
country — in Isaiah. 

35 



36 RESEARCH IN CHINA. 

Sinian not far away, at Nan-t'ang-mel, and probably equivalent to the 
Hu-t'o system, which is separated from the Sinian by a decided break. 
Where it exists, the unconformity is everywhere taken as the dividing plane 
and the equivalent horizon must elsewhere determine the limits of Cam- 
brian upon pre-Cambrian, even though the strata be locally conformable. 
Hence we are constrained to exclude from the Sinian certain limestones, 
which von Richthofen regarded as "Untersinisch," but which in all prob- 
ability represent deposits that are pre-Sinian. 

Thus used to name a series of conformable strata deposited during the 
great Cambro-Ordovician transgression of Asia, the term Sinian has wide 
correlative application, since a similar transgression spread over much of 
North America and Europe and was there accompanied by evolution of 
faunas closely related to those of Asia. From Cambrian to Ordovician 
there is general continuity of physical conditions and faunal evolution. A 
natural plane of division marked by unconformity frequently occurs near 
the middle Ordovician. The strata below that plane to the base of the 
Cambrian may be appropriately called Sinian.* 

Von Richthofen gives the following description of the Sinian in his 
chapter on the rocks of Liau-tung :f 

The above-described stratigraphic fact [a marked unconformity of dip] sharply dis- 
tinguishes the formations which have been described [pre-Cambrian metamorphic rocks 
and intrusives] from a series of strata which we found to be widely distributed along 
our route. In regular succession they follow one another. They everywhere exhibit a 
richly varied stratification, which in the upper part is somewhat monotonous, but in the 
lower shows many peculiarities in consequence of the fact that the strata, which were 
deposited upon a sea bottom that was set with reefs, extend in some regions deeper than 
in others. At a certain horizon which is high in the series we found globulitic limestones 
that are especially distinct and afford a paleontological clue. According to a communica- 
tion from Mr. Dames the trilobite fauna of Sai-ma-ki and the Tai-tsze valley consists 
essentially of the genera Dikelocephalus and Conocephalus, and is closely related to the 
fauna of the Potsdam sandstone of New York, Wisconsin, Iowa, and Minnesota, especially 
the province of the upper Missouri, and the relation is such that there is indeed no doubt 
of their equivalency. In the Fortieth Parallel survey the same fauna has been recognized 
by Hall in the mining districts of White Pine and Eureka. It seems that the Chinese fauna 
more closely resembles the American Potsdam fauna than the Swedish Cambrian. It 
has nothing in common with the Bohemian primordial fauna. 

It is not appropriate to apply the name Cambrian immediately to the formation under 
discussion. For, until it may be possible to distinguish the paleontological horizon, we 
are obliged to assign to it an extraordinarily long sequence of strata, which constitutes a 
great whole in consequence of stratigraphic conformity, without any possibility of proving 
that the beginning and end correspond with those limits within which the name Cambrian is 



* A. Geilrie has translated the German term "Sinisch" as "Sinisian." The original English form used 
by the author of the name is 
t China, vol n, pp. 107-108. 



iiq^,:. m 9$ 



TYPE SBCTION OP SINIAN. 37 

applied in Europe and America. It is, moreover, possible that the formation in China, in 
which strata containing the primordial fauna have indeed a definite but somewhat subor- 
dinate position, reaches much further down and therefore comprises a much longer period, 
while it also probably extends without noticeable interruption up into the lower Silurian. 

SINIAN IN CHINA. 

When asked to suggest a district in which the Sinian might be studied 
in typical character, von Richthofen referred us to Liau-tung and Shan- 
tung, the northeastern provinces of China. The conditions immediately 
preceding war rendered surveying in Liau-tung difficult at the time of our 
expedition, and Shan-tung became the scene of our detailed studies. 

The Ch'ang-hia and Sin-t'ai districts which were selected for detailed 
topographic and geologic surveys are represented in plates xiii and xiv, 
volume 1, and the local variations of strata are described by Blackwelder, 
volume 1, chapter 11. The general sequence consists of three well-defined 
divisions between two unconformities, as follows: 

Unconformity by erosion. 

Tsi-nan limestone (lower Ordovician). 

Kiu-lung group, interbedded limestone and shale (Upper and Middle Cambrian). 

Man-t'o shales (Middle and late Lower Cambrian). 

Unconformity by dip. 

Pre-Cambrian rocks. 

Lower Sinian. — In Shan-tung, Liau-tung, and Shan-si, that is, through- 
out northern China, the characteristic strata of the Lower Sinian are red 
deposits, which we have called the Man-t'o formation. They are probably 
equivalent to von Richthofen's Tung-won Schichten. In Central China, on 
the Yang-tzi'-kiang, we saw nothing corresponding to the Man-t'o formation, 
the Sinian being composed of limestone, apparently to the very base. 

The typical red shale of the Man-t'o formation passes into red or 
chocolate-brown shaly sandstone and is interbedded with thin but some- 
times persistent layers of gray to cream-colored limestone. The thick- 
ness varies from 350 to 550 feet, 105 to 165 meters. The basal layers 
occasionally show local conglomerates, as at Nan-t'ang-mei, Shan-si, where 
a body of chert conglomerate rests upon cherty Proterozoic limestone, 
and south of Timg-yu, Shan-si, where the underlying slates of the Hu-t'o 
system constitute pebbles in the Man-t'o next the contact. Usually, how- 
ever, the material adjacent to the eroded surface of pre-Cambrian rocks is 
highly oxidized residual soil or fine calcareous sediment, which is in either 
case foreign to the underlying metamorphic rocks. 

The sandy red mud of the Man-t'o formation is an end-product of 
mechanical and chemical rock decay. Only the most enduring minerals, 



38 RSSSARCH IN CHINA. 

quartz, clay, and oxide of iron, remain in notable quantities. The material 
resulted from disintegration of crystalline rocks under climatic condi- 
tions favorable to oxidation, or passed through stages of accumulation 
as a continental deposit, during which it was subject to such conditions, 
and was laid down without undergoing chemical reduction or abrasion or 
sorting. The rock is red throughout, as the Permian and Triassic sand- 
stones are, and like them was not only originally a red mud, but formed 
a red deposit. It did not become blue, as the red muds of Virginia now 
do in Chesapeake Bay in consequence of abundant organic matter. The 
persistence of red in the Man-t'o formation shows that organic substances 
were not present in quantity. 

Waves, of which ripple marks on the sandy shales are here and there 
evidence, accomplished but little work in the way of sorting. They were 
evidently too weak to sort sediment in which the proportion of mud was 
so great. 

Calcareous layers occur in the Man-t'o formation occasionally very 
near the base, persistently at horizons ioo to 150 feet, 30 to 45 meters, 
higher up, and again, less commonly, near the top, which is often sandy. 
A transition into the overlying limestone of the Kiu-lung group is formed of 
interbedded brown shale and gray limestone. Individual limestone strata 
are very uniform in thickness, though but a few inches, or at most 10 feet, 
thick and not of great extent. The more continuous are those near the 
middle of the formation, which were found in all the sections in the Ch'ang- 
hia and Sin-t'ai districts in Shan-tung. 

The interbedding of the shale and limestone is irregular; it does not 
follow any rhythm. It is apparent that local conditions were unlike in 
adjacent waters at any one time and varied in unlike manner from time to 
time ; but red sediment from the land or calcareous sediment from the sea 
was deposited at any time. The condition which favored precipitation 
of lime, whether chemically or organically, was continuously present and 
became effective whenever the environment became right; and so with 
the mud. It is not possible to assume that the limestones were laid down 
in deep waters; they are too closely related to the shales and sandstones 
which were deposited in shallows. As the limestones are relatively free 
from clay, and what they do contain is very fine, the lime-depositing waters 
were comparatively clear, and this clearness appears to have been the 
essential condition. 

One may form a concept of the conditions somewhat as follows : Along 
the flat, red shore of the Man-t'o sea, bars and islands formed where streams 
emptied, and shut off the mud-carrying currents from intermediate stretches 
of coast. More or less extensive lagoons were thus produced and within 



SINIAN GLACIAL DEPOSIT. 39 

these the waters were clear. Being partly closed and shallow, they were 
relatively warm and liable to maximum evaporation. Rippling of the 
surface favored precipitation of lime carbonate by agitation. Warmth 
and protection invited organic life, both plant and animal, which probably 
occupied the lagoons in low forms that did not become fossil before 
trilobites, the earliest that have been preserved, discovered the habitat. 

The description of the Man-t'o formation has thus far dealt with it 
as it is developed in northern China. The red mud does not occur in the 
south on the Yang-tzi'-kiang, where we saw the base of the Sinian, but the 
strata which we suppose to be equivalent are thin-bedded gray limestones 
which rest on a well-defined glacial till. The latter was seen only near the 
village of Nan-t'ou, and we have named it the Nan-t'ou tillite. 

Nan-Vou tillite. — The Nan-t'ou glacial deposit occurs in longitude 
iii° east, latitude 3 1° north, about 200 feet, 60 meters, above sea. It 
evidently accumulated close to sea-level in early Sinian time, as it is 
overlain by marine limestones of that age. At the base the plane of the 
pre-Sinian unconformity is characteristically developed and covered by 
a cross-bedded quartzite, which may have been either river deposit or 
beach. The top of the quartzite is generally covered in the type locality 
and a cultivated slope interrupts the section for 100 feet, 30 meters. Above 
the terraced fields occur steep banks of tillite, a greenish rock, about as 
hard as unweathered shale, of irregular hackly fracture, not stratified, and 
containing pebbles and boulders of various kinds and sizes, many of which 
are striated. The thickness seen is 120 feet, 36 meters. 

At the top of the tillite, beneath a cliff , is a well-exposed contact with 
the overlying limestone. The tillite passes into a greenish shale, consisting 
of the same materials, including characteristic pebbles, all rearranged by 
water. This shale conglomerate is about 2 feet thick and grades into the 
overlying limestone, the basal layer of a great thickness of Sinian. 

The facts clearly demonstrate the presence at this spot of a glacier 
which gave way to marine waters and left a deposit of till that was slightly 
washed by waves before it was buried beneath calcareous mud. 

The glacial deposit was seen only where it is exposed in the gorge of the 
Yang-tzi'-kiang, beneath limestone cliffs. Both northward and southward 
from the river the escarpment stretches beyond sight, and continuous 
below it is the slope which, at the river, is formed of the tillite; but so 
common a topographic feature as a slope below a cliff affords little ground 
for inferring the extension of so unusual a deposit as an early Cambrian 
till, and we limit ourselves to the positive statement of occurrence at 
Nan-t'ou. 



40 RSS8ARCH IN CHINA. 

Whether the Nan-t'ou glacier was an exceptional occurrence or a rep- 
resentative of an extensive system, only in degree affects the deduction 
that the temperature of early Sinian time was low. Glaciation in latitude 
31 near sea-level presents, it is true, a problem which refrigeration alone 
will not solve, especially as no traces of contemporaneous glaciers have been 
found further north ; but there can be no doubt that it signifies severe cold 
throughout northern Asia. The fact agrees with the inference which may 
be drawn from the red sediments of the Man-t'o. That they were not 
reduced by organic matter proves the barrenness of the shores and seas, 
although life was abundant elsewhere before and during the Man-t'o epoch 
and soon after developed richly in the shallows ; that it was at first absent 
and when it appeared in the sea was limited in variety may be attributed 
to the low temperature. 

Aridity was also probably a condition of the climate. Slight precipi- 
tation prevents glaciation, even under conditions of severe cold, as is the 
case in northern Siberia, and the absence of glaciers in the north in early 
Sinian time may thus be understood. 

Middle Sinian, Kiu-lung group. — The Kiu-lung group of Shan-tung is 
a succession of limestones and shales which immediately follows the Man-t'o 
formation. Transition beds connect the two. Shale is a common rock in 
both, but in the Man-t'o it is red, whereas in the Kiu-lung it is green. Lime- 
stone is thin-bedded and subordinate in the former, in the latter it is usually 
massive and predominant. The Man-t'o contains a sparse Middle or Lower 
Cambrian fauna in its upper portion; the Kiu-lung carries very abundant 
faunas, which range from Middle Cambrian at the base to Upper Cambrian 
and possibly to lowest Ordovician at the top. 

This Cambrian group was clearly recognized in Shan-tung, but not as 
distinctly elsewhere. In Shan-si it is represented by the lower part of the 
Ki-chou limestone, which comprises all the Sinian except the Man-t'o shale ; 
and on the Yang-tzi the Kiu-lung horizons are within the great limestone 
formation, which is the whole Sinian system. 

I proceed to consider the Kiu-lung group as it occurs in Shan-tung. 
The type locality is the Kiu-lung range, a chain of hills which borders the 
W6n-ho valley on the south, southeast of the district town of Lai-wu-hi£n, 
longitude 117 40' E., latitude 36 15' N. The strata dip gently northward 
and are extensively exposed from the Man-t'o shale below to the Tsi-nan 
limestone above. The thickness is 900 to 1,000 feet, 275 to 335 meters. 

The component strata are of green shale and limestone. The latter 
presents several distinct varieties: massive black to gray oolite, nodular 
or conglomeratic layers of shale, and uniform fine-grained blue limestone. 
These occur from the bottom up, in the order named, of such thickness and 
extent as to be considered distinct formations in some districts. 



CHARACTER OF MIDDLE SINIAN. 41 

The black oolitic limestone, which commonly but irregularly occurs 
in the green shale above the red Man-t'o, reached a maximum thickness, 
as we observed it, of 550 feet, 165 meters, near the village of Ch'ang-hia,* 
and we called it the Ch'ang-hia oolite. In consequence of its massive 
character and vertical jointing it there forms imposing cliffs, and one does 
not suspect that it may, in a short distance, thin out to a layer of vanish- 
ing lenses. Such is, however, the case, as we found in the district north 
of Sin-t'ai-hi6n, where a stratum 100 feet, 30 meters, thick gave out in 
less than a mile. The color of the rock is due to the black oolites, with 
which it is usually crowded. Blackwelder has described their peculiarities, f 
and he finds that there is a series of forms ranging from true oolites, 
which exhibit a nucleus and concentric banding, through grades of finer 
to coarser crystalline texture, to a single crystal ; and he concludes that all 
the bodies had a common origin as oolites, which formed concentrically 
around a nucleus. Some have remained but little altered and show the 
original structure, while others have more or less completely crystallized. 
Crystallization has progressed from a primary condition of many minute 
crystals toward an ultimate development of a few or one large crystal. The 
fossils of the Ch'ang-hia limestone are trilobites, brachiopods, etc., of Middle 
Cambrian age. 

The middle portion of the Kiu-lung group is characterized by the 
predominance of shale. In the vicinity of Ch'ang-hia a single stratum 150 
feet, 45 meters, thick was so clearly distinct that we described it as a sep- 
arate formation, the Ku-shan shale. In the Kiu-lung hills and adjacent 
areas, however, no individual shale formation was distinguishable, the mass 
of shale and limestone layers being on the whole thicker, but irregular. 

A special interest attaches to this member, since conglomeratic lime- 
stones, such as have been described by Walcott as " intraf ormational 
conglomerates," are of common occurrence in it. These peculiar rocks 
consist of an earthy calcareous matrix, in which flat, pebble-like bits of 
limestone are irregularly embedded. The pieces are commonly rounded, 
but sometimes sharply broken; they are fragments of thin limestone sheets, 
which were broken up, washed, and rearranged during the formation of the 
stratum in which they occur. Among the hypotheses that have been sug- 
gested to account for these conglomerates, we are restricted to those which 
regard the pebbles and the matrix as essentially contemporaneous. The 
fact of unbroken conformity with the immediately underlying stratum, 
which has been observed in every instance, excludes any hypothesis that 
presupposes unconformity and erosion of older rocks. Identity of earthy 
calcareous composition of pebble and matrix, and particularly identity of 

♦Vol. i, Plate xiii. 
t/tai, p. 30. 



42 RESEARCH IN CHINA. 

fossil content in both, confirms this. Characters common to shoal-water 
deposits mark these beds, which, though most frequent in the middle of the 
Kiu-lung group, occur also in the underlying Man-t'o. The conditions of 
occurrence, the constitution, and the detail of the conglomeratic layers 
require that during the deposition of calcareous mud in shallow waters there 
shall have been some layers that hardened more or less firmly to limestone 
strata. There is no evidence that they were extensive or continuous; they 
may probably have been limited and separate; but they were common. 
The mud containing these layers was disturbed and the more or less con- 
solidated lime rock was broken, washed, and redeposited, after the manner 
of a conglomerate. A portion of the process as yet eludes interpretation. 
We do not know the physico-chemical or organic conditions under which 
limestones consolidate, and are therefore at a loss to understand why some 
layers or nodules harden before others. Our speculations are given in vol- 
ume i, part ii. 

The upper part of the Kiu-lung group is a thick-bedded uniform lime- 
stone, of light-blue to gray color and usually smooth texture. From its 
development near the village of Ch'au-mi-ti£n in the Ch'ang-hia district, 
we called it the Ch'au-mi-ti£n limestone. Its thickness is about 580 feet, 
175 meters, in the type locality, where it directly overlies the Ku-shan 
shale. In Kiu-lung hills the rock occupies a similar stratigraphic horizon 
and carries the Upper Cambrian fossils, which characterize it in the type 
locality, but its limits are not so clearly defined. In marked contrast to 
other Sinian strata below it, the Ch'au-mi-ti&i limestone is horizontally 
continuous and uniform. It represents a wide-spread condition of deposi- 
tion, such as the circulation of a broad marine current over a continental 
shelf, and thus differs from the strictly httoral aspects of the Man-t'o 
terrane, and the inconstant phases of the shaly part of the Kiu-lung 
division. 

Upper Sinian. — The Tsi-nan limestone, so named after the capital 
city near which it is exposed, is the highest formation of the Sinian system 
in Shan-tung. It differs from the underlying Ch'au-mi-ti&i, being less 
plainly stratified, dark gray to brownish in color, and poor in fossils, which 
are of lower Ordovician types. It may commonly be divided into two 
members: a lower, 250 feet, 75 meters, thick, consisting of shale and coarse 
crystalline dolomite, which weathers like calcareous sandstone; and an 
upper, 2,500 feet, 750 meters, or more, which is dolomitic limestone. The 
total thickness is indeterminate, since the upper surface is one of erosion, 
even where it is covered by later sediments. 

This Ordovician limestone was confused by von Richthofen, who found 
no fossils in it, with the very similar Carboniferous formation that he had 



DIVISIONS OF THE SINIAN. 



43 



correctly identified in southern China, and it is erroneously represented 
as ' ' Kohlenkalkstein ' ' in his published maps of northern China. Lorenz* 
in 1902 and Blackwelder in 1903 independently recognized its Ordovician 
relation on the basis of few but characteristic fossils. Weller has described 

our collections, t 

Sinian in general. — The development of the Sinian system in Shan- 
tung, where the Man-t'o red shales, the Kiu-lung group of green shale and 
varied limestone, and the Tsi-nan dolomitic limestone are distinguishable, 
is better known to us than the sequence of corresponding strata in any other 
province. The Man-t'o is present in northwest Chi'-li and Shan-si, and is 
there followed by peculiar limestones like those of the Kiu-lung. Von 
Richthofen observed the same characteristic rocks in northern Ho-nan, 
latitude 34 30'. % The red shale is wanting in the sections we saw on the 
Yang-tzi-kiang, but the conglomeratic and oolitic limestones are present. 
These varied relations led us to apply local names to the divisions which 
are unlike in different provinces. Their correlative significances are given 
in the following table: 



System. 


Shan-tung. 


Liau-tung. 


Chili and Shan -si. 


Ssl-ch'uan and Hu-pel. 


Sinian 


(Tsi-nan limestone ) 
-Kiu-lung group / 
(Man-t'o shale 


Fu-ch6u ? group 
Yung-ning sandstone 


Ki-ch6u limestone 
Man-t'o shale 


Ki-sin-ling limestone 
Nan-t'ou tillite 

> 



The following paragraphs contain a summary of our observations 
regarding the Sinian in Shan-si and the Ki-sin-ling limestone of the Yang- 
tze gorges, Hu-pe'i. § 

In northern Shan-si, about the Wu-t'ai-shan, the Sinian is exposed 
in characteristic development, with the Man-t'o at the base and the cal- 
careous strata in great thickness above. The lowest stratum of the Man-t'o 
is frequently a conglomerate of pebbles of the subjacent rocks, and the 
materials of the formation are, throughout its thickness, coarser than is 
commonly the case in Shan-tung. The characteristic yellowish limestones 
occur, but generally high up and in two or three layers only. The total 
thickness is 180 to 335 feet, 55 to 100 meters. 

Strata of gray to greenish shale and oolitic as well as conglomeratic 
limestone, aggregating about 600 feet, 180 meters, succeed the red rocks 
and correspond to part of the Kiu-lung group. Above these follow massive 

* Beitrage zur Geologic und Paleontologie Shan-tungs, Lorenz, part I. 

f Vol. in of this work. 

{China, vol. n, p. 505. 

JFor fuller details see vol. 1, chapters vi and xu. 



44 RESEARCH IN CHINA. 

limestones, which are the equivalents of the Ch'au-mi-tten and Tsi-nan 
divisions and compare with them in massiveness. The total thickness of 
the system in northern Shan-si is not far from 4,000 feet, 1 ,200 meters. 

On the middle Yang-tzi, in Hu-pei and eastern Ssi'-ch'uan, the Sinian 
is represented by a limestone which is 4,500 to 5,000 feet, 1,350 to 1,500 
meters, thick. The great formation is probably capable of subdivision on 
lithologic and paleontologic differences, but the distinctions are less marked 
than in Shan-tung or even in Shan-si. Regarding it as a whole it may be 
called the Sinian limestone, but to give it sharper definition we apply the 
name Ki-sin-ling, from the pass of that name where the provinces of Hu-pei, 
Ssi-ch'uan, and Shen-si corner. It is there typically exposed, and both 
Cambrian and Ordovician fossils were found in nearby sections. 

At the base of the Ki-sin-ling limestone, at Nan-t'ou on the Yang-tzi, 
is a basal conglomerate of pebbles derived from the underlying tillite, 
embedded in greenish shale. It is but two feet thick and is succeeded by 
thin-bedded, shaly, oolitic, and in part chert-bearing limestones, 350 feet 
thick. We did not see the bottom of the formation in any other section, 
but the thin-bedded limestones probably appear in the gorges of the Yang- 
tzi and in the mountains near the Ki-sin-ling. 

The upper and major part of the Sinian in the Yang-tzi sections is 
massive dark-gray or liver-colored limestone, free from chert. It is prob- 
ably nearly 4,500 feet, 1 ,350 meters, thick. Farther north in the Ki-sin-ling 
pass, it consists of thinner bedded, more carbonaceous or bituminous 
strata. It is, however, in all its phases a great marine limestone. 

The upper limit of the Ki-sin-ling is indeterminate, as there is a tran- 
sition from it into interbedded shale and limestone, which passes upward 
into the overlying Sin-t'an shale. The transition strata are between 200 
and 300 feet, 60 to 90 meters, thick, and at Sii-kia-pa in Ssi-ch'uan they 
yielded middle Ordovician (Trenton) fossils. The horizon is lithologically 
distinguished by a peculiar stratum of black chert or lydite, which was also 
found by von Richthofen and L6czy in sections north of Kuan-yiian-hten, 
Ssi-ch'uan, 200 miles, 300 kilometers, northwest of Sti-kia-pa. 

The age of the lower part of the Ki-sin-ling is not definitely fixed, as we 
found no fossils at Nan-t'ou, where the base is exposed; and those which 
we did find elsewhere were obtained from pebbles. They were picked 
up on a river bar of the Nan-kiang, near Ch6n-p'ing-hi6n, Shen-si, where 
strata of the Ki-sin-ling form the canyon walls, and they no doubt came 
from the immediate vicinity and from the lower part of the limestone. 
They comprise Lower Cambrian Obolus asiatica as well as lower Middle 
Cambrian types, and represent the top of the Man-t'o and base of the 
Kiu-lung group of Shan-tung. 



SINIAN IN THB TS'lN-UNG. 45 

The Ki-sin-ling thus includes at least upper Lower Cambrian at the 
base, and extends up to middle Ordovician (Trenton), at which horizon 
it passes by transition into shales, which are probably of Silurian or 
Devonian age. 

Sinian strata are not definitely known by fossils to occur southeast of 
the Yang-tzi* in southeastern China, but both von Richthofen and L6czy,* 
with strong probability, refer certain strata, the Ta-ho grits and Lu-shan 
slates, to the period. 

Sinian strata have not been recognized in characteristic limestones or 
identified by fossils in the Ts'in-ling-shan, yet they are in all probability 
present. Von Richthofen did not hold this view. f He wrote: 

The eastern Kuen-lung remained free from the Sinian transgression south of the 
northern base of the Fu-niu-shan and the Ts'in-ling-shan, and the adjacent region on the 
south. 

Briefly the facts are as follows : In three sections across the Ts'in-ling 
range, observed by von Richthofen % and ourselves, metamorphic schists of 
the Wu-t'ai type are succeeded by a basal conglomerate, quartzitic rocks, 
and gray limestone. There is a great series of slates, and also carbonace- 
ous limestone, which locally carries coal. Our observations of the relations 
of these strata are delineated on the geological atlas sheet ai, and while not 
conclusive, they indicate that the order of stratigraphic sequence is from the 
conglomerate, through quartzite, limestone, and slate, to the coal-bearing 
limestone. We agree with von Richthofen that the last-named is Carbon- 
iferous, but think it is distinct from the gray limestone, which corresponds 
with the Ki-sin-ling (Sinian) in position beneath a thickness of middle 
Paleozoic shales. If our understanding is correct, the Sinian is present in a 
mid-section of the Ts'in-ling-shan, near the northern base of the range. 

There is but little knowledge regarding the Sinian system northwest of 
the Ts'in-ling-shan. L6czy assigns various occurrences of limestone, which 
he describes as early Paleozoic, to the system, but as a rule, in the fact that 
they are highly siliceous, they much more nearly resemble the pre-Cambrian 
limestones of the Nan-k'ou system than they do the Sinian. However, in 
the vicinity of Qu6-ta, latitude 36 , longitude 102 , west of Lan-ch6u-fu, he 
observed in a small mountain range known as the "Cha-ji-shan" a heavily 
bedded limestone, in part dark and bituminous, in part lighter colored and 
somewhat interbedded with shale and sandstone, which exhibits an oolitic 
nodular structure such as is found also in the globulitic limestones of the 
Sinian. He regards this as a characteristic occurrence of the Sinian lime- 

♦Reisc des Grafen Sz&henyi, vol. 1, p. 380, map. 
t China, vol. n, p. 713. 
\lbid. t vol. n, p. 565. 



46 RESEARCH IN CHINA. 

stone of sufficiently definite character to justify the identification of it and 
other limestones of the region as belonging to that system. 

In the preceding pages the occurrence of the early Paleozoic (Sinian) 
strata has been described for various districts of China, from the province 
of Liau-tung, latitude 41 , to the Yang-tzi in latitude 30 ; and from the 
eastern plains of the empire to the central Ts'in-ling-shan, in longitude 108 . 
It remains to consider the probably equivalent terranes which are known 
in the Himalayas. 

In southwestern China rocks of early Paleozoic age, if they occur, are 
highly metamorphosed and have not yet been definitely recognized. It is 
not until we reach the central Himalayas, in longitude 8o°, that we have 
any precise information. Thence westward, in the regions covered by 
Griesbach* and Hayden,f there exists, on the basis of fossils, definite 
evidence of the presence of the Upper Cambrian, which is underlain 
by a considerable thickness of conformable strata, presumably also of 
Cambrian age. 

Griesbach calls these strata by the local name Haimantas, and gives 
the following classification for the eastern area : 

In descending order: 

Silurian : 

3. Series of quartz shales and slates. 

2. Shales and silky phyllites, with great thickness of quartzites. 
Haimantas: 

1. Quartzite, generally purple, with great thickness of conglomerate. 
Vaikritas and older gneiss. (Pre-Cambrian.) 

The total thickness is estimated at about 4,000 feet, 1,200 meters. The 
base where the Haimantas come in contact with the Vaikritas exhibits no 
sharply defined plane of division : 

At Milam, for instance, there is seemingly a very gradual passage from the micaceous 
schist south of that village, into greenish-gray phyllites and talcose schists with garnets of 
the Vaikritas, and finally into the thin-bedded quartzites, shales, and conglomerates of the 
Haimantas, and the change is so gradual that the boundary line could not be drawn with 
anything like accuracy .{ 

Regarding the conglomerate, it is said (page 51) : 

The thick deposits of a coarse conglomerate and breccia are mostly made up of rolled 
and subangular fragments of rocks belonging to the crystalline area, and amongst them 
large boulders of quartzites and gneissose rocks seem to predominate. The matrix in which 

* India Geological Survey Memoirs, vol. xxm, Geology of the Central Himalayas, by C. L. Gries- 
bach, 1891. 

Ildem, vol. xxxvi, pt. I, Geology of Spiti, with parts of Bashahr and Rupshu, by H. H. Hayden, 
1904. 

%Idem, vol. xxm, p. Si. 



CAMBRIAN IN THE HIMALAYAS. 47 

these boulders are firmly embedded is nearly always a hard flinty quartz rock, sometimes 
partially schistose. It is by far one of the most characteristic and easily recognized hori- 
zons of the central Himalayas, and is invariably met with in all Haimanta sections which I 
have seen. 

Again on page 96 : 

This conglomerate, which in places strongly resembles a boulder-bed, merges into 
massive, intensely hard, dark-purple quartzites. 

And on page 159: 

The mineralogical character of the shales and quartzites lying below the typical 
purple quartzites with the boulder-bed (conglomerate) and the adjoining metamorphic 
schists, Vaikritas, merge into one another. 

It is of interest to note the descriptive term, " boulder-beds," by which 
the conglomerates of the early Cambrian are designated, since we have dis- 
covered glacial deposits, probably of that age, on the Yang-tzi, in a region 
which, though 1,850 miles, 3,000 kilometers, distant, is practically in the 
same latitude, 31 north. However, the conglomerate was not regarded as 
a true boulder-bed of glacial origin by Griesbach, who, with reference to 
the ancient shore-line in the western Himalayas during the Haimanta age, 
states that he regards these deposits to be evidence of "a chain of eleva- 
tions, from the waste of which the boulders and pebbles of the Haimanta 
conglomerate were derived." An inquiry addressed to Dr. Holland, the 
present director of the Indian Survey, has brought a negative, though 
perhaps not decisive, answer: 

The question of the possible existence of Pre-Carboniferous glacial deposits in India is 
one which has recently received considerable attention. You are, no doubt, familiar with 
the published description of the Blaini boulder slate of the Simla area, the glacial origin of 
which is generally admitted. This formation was, until recently, regarded as possibly of 
Upper Paleozoic age, corresponding to the well-known Talchir and Salt Range boulder- 
beds ; but there has been of late a general tendency to correlate the series of beds with which 
it is associated with the old, probably Pre-Cambrian, sediments of the Peninsula. I first 
drew attention to this in my General Report of the Geological Survey (1903-04) published 
in Records Geological Survey of India, vol. xxxn (page 156) and the conclusion based 
admittedly on negative evidence has received some support from the recent discoveries of 
Pre-Cambrian boulder slates both in Australia and in South Africa. In this connection, 
the occurrence of a typical boulder slate among the pre-Vindhyan rocks of the Son Valley in 
Rewa State is also of considerable interest (Memoirs, Geological Survey of India, vol. xxxi, 
p. 132) ; but it should be remembered that no striated boulders have been found in the 
Himalayas or in the Son Valley. 

The possibility of the occurrence of a representative of the Blaini boulder slate in associ- 
ation with the fossiliferous beds of Gurhwal and Kumaon has been steadily kept in view dur- 
ing the progress of geological surveys in the Himalaya, and it may be assumed that, during 
his survey, Mr. Griesbach would have had this in mind when studying such a rock as the 
boulder-bed that he describes, and would have been on the lookout for evidences of glacial 



48 RESEARCH IN CHINA. 

action. The same bed, however, is well known to Mr. C. S. Middlemiss, who had the 
opportunity of visiting many of the sections in Mr. Griesbach's company. Mr. Middlemiss 
states that the conglomerate bears no resemblance to a till, the matrix being a quartette. 
The term "boulder-bed" has been applied to the Haimanta rode merely on account of the 
presence in it of unusually large boulders. 

The middle and upper divisions of the Haimantas are thus characterized 
(pages 52 and 53) : 

The purple quartzites and conglomerates are in all sections overlain by a great 
thickness of bluish-gray phyllites, shales, and thicker bedded quartzites, traversed by many 
quartz veins. Towards the upper portion of it reddish-brown or pink quartz shales are 
intercalated. * * * The only fossil traces known from this system have been found 
in shales in this division. None of these organic remains are more than traces. They 
are: crinoid? stem impressions; bivalve? casts and numerous casts of Belkrophon sp. 
The latter occur both in the purplish-pink quartzite and in the shales accompanying it, 
and rather high up in the sequence of beds of this division. 

In all the central Himalayan sections through the Haimantas, from the Kali river to 
the Spiti province, I have invariably found certain beds which constitute the third division. 
They consist of two zones of very hard quartz shales, the lower of which is formed by 
densely red and pink quartz shales, which pass upwards into greenish-gray quartzite and 
shales with pink shaly partings; the whole, as far as I know, quite unfossiliferous. 
Together these beds are not more than 250 to 500 feet in thickness. 

In his account of the geology of Spiti (page 13) Hayden discusses dif- 
ferences of observations by himself and Griesbach, and bases his conclu- 
sion upon his own work, which in that region was the more thorough of the 
two. He fails to find any conglomerate which could be supposed to belong 
to Griesbach's lower Haimanta conglomerate, except in one instance in 
which the rock is clearly autoclastic. This difference may perhaps find its 
explanation in the suggestion of a glacial origin of the conglomerates, since 
they might in that case be of peculiarly local occurrence. After referring to 
the lower beds as slates, quartzites, and grits, Hayden proceeds (page 13) : 

The overlying beds, which presumably comprise Mr. Griesbach's upper Haimantas, 
consist of a series of black, purple, and gray slates, with gray, green, and red quartzites. 
The lower part of the series is chiefly argillaceous and the upper mainly siliceous. * * * 
Among the argillaceous beds are bands of an intensely blade carbonaceous shale, resem- 
bling the carbonaceous shales of Simla. * * * 

In the Parahk) valley the upper siliceous beds pass up gradually into a series of gray 
and green micaceous quartzites and thinly foliated slates and shales, with narrow bands 
of light-gray dolomite. 

The slates, which are usually dark blue or black, vary in composition from a soft 
argillaceous rock to a hard siliceous variety with much mica. * * * The slates are 
interbedded with great irregularity with gray, yellow, or whitish quartzites which are 
almost invariably capped by a narrow band of either calcareous quartzite or dolomhic 
limestone only a few inches in thickness. The limestone, which is gray on fresh fracture, 
weathers to a pinkish or brownish red and is again overlaid by slates which are at first argil- 



ORDOVTCIAN WARPING. 49 

laceous, but gradually become more and more siliceous till they pass up again into quartz- 
ites. This alternation continues with great regularity for many hundred feet. Towards 
the top of the series the argillaceous beds give place to light-colored siliceous slates and 
thin-bedded flaggy quartzites, with bands of red and pink dolomite, which latter gradually 
increases in frequency and thickness till it becomes the predominant rock. These beds 
constitute the oldest fossiliferous series hitherto found in Spiti. 

After the statement of a detailed section, which comprises 1,188 feet, 
371 meters, of strata, there follows the account of the fossils. Near the base 
of the section, in a hard calcareous and micaceous quartzite, occur numerous 
valves of a small brachiopod resembling Lingulella, with which are associated 
indeterminate fragments of the head shields of a trilobite. About 400 feet, 
120 meters, higher, trilobite remains are again abundant but poorly pre- 
served. One hundred and sixty feet, 48 meters, still higher up, large num- 
bers of specimens were collected in a very fair state of preservation. They 
are said to consist chiefly of species of Ptychoparia, Cor da, and allied genera. 
A hundred feet, 30 meters, higher Ptychoparia is still found and with it large 
numbers of fragments of Olenus sp. and Dikelocephalus sp. About 90 feet, 
27 meters, still higher occur the uppermost determinable fossils, among 
which Ptychoparia is rare and Olenus common. Although the collections 
which are thus briefly described had not been studied, the forms recognized 
are considered sufficient to warrant the inference that the fossiliferous beds 
are of Upper, possibly also of Middle, Cambrian age. 

POST-SINIAN DIASTROPHISM. 

Sinian strata are commonly parallel in attitude with late Paleozoic 
strata, where any such are present. The areas in which the sequence is 
apparently immediate and sedimentation was continuous are limited, so 
far as we know, to Central China; those strata that immediately succeed 
are distinctly terrigenous sediments, which contrast decidedly with the 
underlying marine limestones and represent a revival of erosion. Those 
areas over which an unconformity of erosion without discordance exists 
are extensive and comprise the Paleozoic of North China. 

From these facts it follows that diastrophism at the close of the Sinian 
time involved broad epeirogenic changes, without marked orogenic disturb- 
ances, within the provinces of eastern Asia. 

An exact date of the movement can not be inferred in the region of 
unconformity by erosion, for it is impossible to determine what strata may 
have been removed from the latest which are there present beneath the 
unconformity. The latest remaining are lower Ordovician; they are over- 
lain by upper Carboniferous ; and it is possible that Silurian, Devonian, or 
lower Carboniferous deposits may have been spread over the area. It 



50 RESEARCH IN CHINA. 

is not, however, probable. Had such later strata accumulated to notable 
thickness over the several hundred thousand square miles under con- 
sideration, they must have been removed before the upper Carboniferous 
was laid down, and they should constitute a notable terrigenous formation 
between the Sinian and Wu-shan limestones in the region of continuous 
sedimentation. The Sin-t'an shale occupies this position, and it is but 1,800 
feet» 550 meters, thick. Considering the extent of the lands from which 
the sand and clay were derived, the volume of the formation represents 
a comparatively thin sheet of material eroded. Further, so far as exten- 
sive, though not comprehensive, observations enable us to judge, the level 
of unconformity does not vary greatly from a general horizon in the upper 
Sinian; that is, the limestone remained practically flat and protected, 
was ultimately bared, and soon after was covered by upper Carboniferous. 
The changes of condition thus indicated are: (1) shallowing of the sea, such 
that the bottom, on which limestone had been accumulating, was scoured 
by marine currents; (2) after an indefinite time, gradual exposure of the 
limestone in a flat coastal plain, where at any one time a narrow belt was 
subject to erosion; and (3) progressive deposition of littoral or continental 
sediments upon the eroded surface. The last occurred not earlier than 
middle Carboniferous, and the other stages cover Devonian, Silurian, and 
upper Ordovician. It is possible to introduce a hypothetical stage of depo- 
sition in this series of events, between 1 and 2, if we assume that the deposit 
over the limestone was eroded in the gradual process of exposure; it is, 
indeed, probable that a thin formation of terrigenous character accumulated 
as a temporary storage of the material of the Sin-t'an formation in its 
passage from the crystalline rocks that yielded the quartz and ferruginous 
clay; but there is no direct evidence of any notable marine formation. 

The date of inception of the epeirogenic movement may be fixed more 
nearly in the region of continuous sedimentation. Transition beds of 
shale and limestone follow the Sinian limestone, and among them occurs 
a stratum which contains a well-characterized middle Ordovician (Trenton) 
fauna. We may regard these transition beds as marking the close of the 
general marine condition and the beginning of the period of little or no 
deposition. In contrast to the areas of unconformity by erosion, the region 
of conformable deposits presumably remained somewhat deeply submerged, 
was not subject to marine scour by currents, and was so distant from the 
lowlands of the time that it received but little sediment. The evidence 
of this appears through consideration of the Middle Paleozoic strata. 

If the preceding discussion proves trustworthy a very interesting 
parallel may be drawn with North America. The Cambro-Ordovician 
transgression there closes with an episode marked by withdrawal of the 



A GENERAL GEOGRAPHIC CHANGE. 51 

epicontinental sea from extensive areas within the continent, and in such 
wise that shallows and archipelagos of low flat islands took the place of 
wide mediterraneans. A similar physical change is indicated for eastern 
Asia. The physical history of both continental regions was one of pro- 
longed submergence, favorable to cosmopolitan evolution, which resulted 
in the development of related faunas in the two areas; and the withdrawal 
of marine waters checked the f aunal variation at the same stage on opposite 
sides of the globe. The geographic change was not occasioned by notable 
disturbances of the continental masses, although there probably was some 
gentle warping ; but it may with reason be ascribed to a decided deepening 
of the ocean basins. The trend of the evidence, which may be traced more 
in detail in America and Europe than at present in Asia, is to establish 
proof of a general lowering of the sea-level, such a change as Suess desig- 
nates a negative eustatic movement.* The world-wide prevalence of the 
preceding marine transgression, its long duration, the corresponding devel- 
opment of identical life conditions and consequently of closely related 
organisms, and the universality of the sea-level datum, all combine to 
render that particular negative movement one of the most definite time 
records in geologic history. 

♦La Face de la Terre, vol. n, p. 841. 



RESEARCH III CHINA 




iillwni Asia ilnrinu the 



it 120T 







IV.— MIDDLE PALEOZOIC 



SILURO-DEVONIAN STRATA OF CHINA. 

The preceding chapter upon the Sinian system deals with the stra- 
tigraphy of the Cambrian and lower Ordovician of eastern Asia. Under 
the division middle Paleozoic I propose to describe the strata which fall 
between the Sinian and the Carboniferous, comprising those assigned to 
the upper Ordovician, Silurian or Gothlandian, and Devonian. 

We may first cite the early observations made by von Richthofen, 
who, in his second excursion into the geologically unknown China, explored 
the lower Yang-tzi', particularly between Kiu-kiang and Nan-king. The 
only account of his observations that I have yet been able to find is 
contained in the proceedings of the American Academy of Arts and Sciences, 
volume viii, May 26, 1869. A number of formations are distinguished by 
local names. Of these the first four, namely, the Ta-ho, the Lu-shan schists, 
the Matsu limestone, and the granite intrusions, elude classification. The 
fifth in von Richthofen's enumeration, namely the Tung- ting sandstone, 
is also of uncertain position, but was supposed by him to extend con- 
formably beneath the Devonian limestone, which is next in the series. 
To this Devonian representative von Richthofen gave the name of Si-ho, 
and he says of it: 

This is a limestone formation only 600 feet in thickness. The rock is full of chert 
nodules and contains numerous fossils, chiefly corals, encrinites, and brachiopods. A uhpora 
repens is of frequent occurrence among them, and other forms, too, indicate a Devonian 
age. The name is derived from a prominent hill generally known as Single Tree Hill, east 
of Nan-long, where I first found the fossils. 

Seventh in the series named by von Richthofen are the Nan-king grits, 
which he described as a gritty and purely quartzose sandstone, mostly red 
but variegated, alternating frequently with a coarse conglomerate of per- 
fectly rounded pebbles consisting exclusively of quartz. In certain dark 
shales which are interstratified occur indeterminable fossil plants. 

Conformably overlying the preceding is the Carboniferous limestone, 
called Ki-tau, a name which takes precedence of all others for this forma- 
tion in China. It consists of three members in this locality, namely (1) a 
lower limestone characterized by Fusulina cylindrica, 1,400 feet, 420 meters; 
(2) black sandy shales, black lydite, and soft sandstone, about 400 feet, 120 
meters, thick, containing in the lower strata especially large specimens of 

53 



54 RESEARCH IN CHINA. 

Productus semireticulatus, accompanied by numerous other brachiopods, 
bivalves, corals, and fenestellas; and (3) an upper limestone more than 
1 ,600 feet, 480 meters, thick, which is separated from a bed of coal of the 
preceding member only by a thin stratum of black; shale and is similar in 
nature to the lower limestone. The Ki-tau corresponds in a general way 
with the Wu-shan limestone. 

The further description deals with beds of Mesozoic and later age which 
rest unconformably upon the Carboniferous. 

A type of the middle Paleozoic is found in central China, in eastern 
Ssi'-ch'uan, southern Shan-si, and western Hu-pei". The region is moun- 
tainous, the strata are folded, and exposures are practically continuous in 
the superb canyons of the Yang-tzi-kiang and its tributaries. 

Descriptions of supposed Devonian rocks in place are given by Pum- 
pelly in his account of the Yang-tzl gorges. The great limestone which rests 
on the pre-Cambrian rocks, and is now known to be of Cambro-Ordovician 
age, was called by him Devonian on the supposition that the fossils of that 
age from China were from the limestone in question. In fact, Devonian 
in that region is either absent or represented by the shale which appears 
immediately above the limestone in several places in the gorges through 
which Pumpelly passed in his adventurous journey.* 

Sections observed by our expedition occur on the Ta-ning-ho, longitude 
no° east, and on the Yang-tzi-kiang, from that meridian east to I-chang.f 
At the base collections of middle Ordovician fossils were obtained from the 
transition strata of the Ki-sin-ling limestone near Su-kia-pa, a village on 
the Ta-ning-ho in eastern Ssi'-ch'uan, latitude 31 40', longitude 109 40'. 
From a local bed at the top, a pink limestone near Ta-miau-ssi, we obtained 
forms which may be Devonian or lower Carboniferous. 

At Su-kia-pa the middle Paleozoic strata lie in a closely folded syncline, 
with nearly vertical dip between outcrops of the underlying Ki-sin-ling, 
(Sinian) limestone. The sequence is continuous, conformable, and appar- 
ently complex ; the following are the principal rocks in order from the top 
downward : 

Massive gray limestone, with abundant black chert nodules and upper Carboniferous 
fossils; base of the Wu-shan limestone. 

Sandy shale, chiefly green, in part black; calcareous, ferruginous, bituminous, and 
coaly near the top; also bituminous and black 200 to 300 feet, 60 to 90 meters, 
above the base; weathers earthy brown and iron stained: total 1,800 feet, 550 
meters; Silurian, Devonian, or lower Carboniferous fossils at the top. 

Gray limestone, 200 feet, 60 meters. 



* Smithsonian Contributions to Knowledge, vol. xv, Geological Researches in China, Mongolia, 
and Japan, during the years 1862-65, R. Pumpelly, pages 5-6. 
fVol. 1, pp. 270-271; atlas sheets d 6 and d 7, geology. 



MIDDLE PALEOZOIC, CENTRAL CHINA. 55 

Black chert, "lydite"; a characteristic stratum which does not, however, always 

occur in its place; checks on weathering into small angular fragments; thickness 

5 feet, 1.5 meters. 
Green shale with numerous nodules of gray to brown ferruginous limestone : 100 feet, 

30 meters ; highly fossiliferous, middle Ordovician (Trenton) fauna. 
Light-gray to bluish limestone, in layers 2 to 6 inches thick, containing Orthoceras and 

coiled gastropods, lower Ordovician ; upper part of the Sinian (Ki-sin-ling) limestone. 

The characteristic green shales of the middle Paleozoic occur in typical 
development on the Yang-tzi-kiang, in longitude no° 45' E., at the village 
of Sin-t'an, and the name is conveniently used to designate the sequence of 
strata between the Ki-sin-ling (Sinian) limestone below and the Wu-shan 
(Carboniferous) above. Transition beds 200 feet, 60 meters, thick connect 
the Ki-sin-ling and Sin-t'an and are characterized by upper Ordovician 
fossils. The top of the Sin-t'an is marked by a distinct but conformable 
contact of shale with the overlying massive Wu-shan limestone. 

From the limits stated it will be seen that the Sin-t'an formation rep- 
resents all of Silurian (Gothlandian) , Devonian, and lower Carboniferous 
time. Including the upper Ordovician transition beds, it is but 2,000 feet, 
600 meters, thick, and as a whole is a rather monotonous clayey, sandy 
deposit, modified by more or less calcareous, ferruginous, or bituminous 
admixture. We were not able to detect any evidence of unconformity at 
the base or top of the formation, nor within it. We regard it as a unit in 
a complete sequence of strata; but it was evident that sedimentation was 
meager during most of the periods represented. While it is possible that 
the deposit accumulated chiefly during some particular epoch, we have no 
clue to that one. 

The fauna found in the limestone nodules in green shale, and in light- 
gray limestone near by is described by Weller in volume in of this series. 
It affords a sound basis for correlation with the Trenton limestone of the 
United States and the Vaginoceras limestone of the Baltic, the relations 
being closer with the latter. The horizon falls in the middle Ordovician. 

Although we repeatedly crossed the strata equivalent to this fossilifer- 
ous bed, both north and south of Sii-kia-pa, none of the party observed 
the fossils at any other locality. We may have overlooked them, especially 
in running the swift current of the Ta-ning-ho and Yang-tzi-kiang in boats, 
but it is probable that the fossiliferous calcareous nodules in the green 
shale are of occasional, not general, occurrence. Where they do occur the 
fossils are conspicuous. 

In general the Sin-t'an formation is apparently unfossiliferous. Its 
bituminous phases have much the character of the middle Devonian shales 
of the eastern United States, and where green and sandy it suggests the 
Chemung. 



56 RESEARCH IN CHINA. 

At the top, in a pink limestone, Blackwelder found a few fossils which 
Girty and Bassler have studied.* They are not able to agree on a definite 
correlation, but state that, whereas the bryozoa indicate an age correspond- 
ing to the American Mississippian, the brachiopods do not resemble any 
Mississippian fauna, and if they stood alone would lead Girty to class them 
as possibly Silurian (Gothlandian) . The presumption is that the horizon 
is at least late Devonian or lower Carboniferous, but if so the fauna is unlike 
others of those times previously collected in China. 

This stratum of pink limestone lies but a few feet below the Wu-shan 
limestone and 1,500 feet, 450 meters, below a thin bed of anthracite, next to 
which Blackwelder collected a Chonetes of upper Carboniferous affinities. 

Silurian and Devonian strata in central China were first described by 
von Richthofen, who came upon them in southwestern Shen-si and northern 
Ssi'-ch'uan, en route from Han-chung-fu, longitude 107 12', latitude 32 50' 
to Kuan-yuan -hien, longitude 106 15', latitude 32 20'. They there form 
the southernmost ranges of the Ts'in-ling-shan, north of the Red Basin 
of Ssi-ch'uan, and are intricately folded and overthrust. The strata are, 
however, richly fossiliferous, and have consequently been well identified. 

South of the town of Ning-kiang-ch6u von Richthofen crossed an 
anticlinal range, overturned toward the south, from which he obtained 
the following section, f (The strata are designated in the accompanying 
figures and discussion by the letters / to e in ascending order.) 

(/) Limestone alternating with other strata, namely, gray, splintery, siliceous lime- 
stone, 15 feet; clay shales; lydite conglomerate, and lydite sandstone. The pebbles of 
the conglomerate in some of the beds are much rounded, in others they are rounded on the 
corners, and in still others they are quite angular and sharp-edged . The sandstones are 
practically a fine-grained conglomerate of the same kind. Thereupon follow, in continu- 
ous alternation, shales and limestones in groups of varying thicknesses. Characteristic 
are : red limestones, red calcareous marls which break up in friable shaly pieces, and also 
green, somewhat crystalline limestone, yellow and green calcareous marls, etc. 

The limestone layers are full of well-preserved fossils; in the upper parts trilobites 
and brachiopods predominate (among them Orihis calligramma and Sfnrifer radiatus) ; in 
the lower, crinoid stems and corals. Dr. Kayser determines the age as middle Silurian 
approximately equivalent to the upper Llandovery. 

Adjacent to the exposures of / and underlying that terrane in the 
overturned limb of the anticline comes a formation k and others in sequence, 
as follows : 

(k) A great thickness of green clay shales, with occasional thin limestone layers, in 
which brachiopods occur. 



♦Vol. i, pp. 273-274. 
t China, vol. 11, p. 596. 



MIDDLE PALEOZOIC, SHE N -SI. 57 

(*) Beds of limestone which contain much clay shale; the limestone consists almost 
entirely of corals in distinct, very well-preserved individuals, which attain more than one 
foot in diameter and are separated by shaly material. Favosites forbesi, Haly sites catenu- 
larius, several kinds of Heliolites, Cyathophyllum, Amplexus, and Alveolites occur, according 
to the determination of Lindstrom, together with other Silurian forms. Crinoids are 
numerous, brachiopods and Orthoceras scarce. Of trilobites I did not find any. 

(h) Green clay shales, which are distinguished by occasional layers full of nodules of 
limestone in bedded form. When weathered these are recognized as the remains of corals, 
which belong to some of the species enumerated in t, but are much smaller. Limestone 
layers of the most varied character and coloring are interbedded with the shales and 
alternate with them, now in thick beds, again in the thinnest layers. The number of 
fossils is extraordinarily great in this easily recognized formation. Every calcareous piece 
exhibits organic structure. Together with the corals occur innumerable long crinoid 
stems, small trilobites, and many brachiopods, especially species of Orthis. The last 
occur in such heaps that they alone constitute single limestone beds. According to the 
determination of Dr. Kayser, the terranes i and h are Upper Silurian, approximately 
equivalent to the Wenlock. 

(g) Gray limestone and soft gray calcareous marl, which, according to the occurrence 
of A try pa reticularis, is Devonian. 

(/) Strongly bituminous limestone of blackish and liver-brown color, which is without 
question identical with the Carboniferous limestone. 

The gray, splintery limestone at the base of this section is not recog- 
nized by von Richthofen as representing the Sinian, but probably is of the 
transition beds, which follow the typical limestone of that system on the 
Ta-ning-ho. As von Richthofen had not distinguished the Sinian from 
the Carboniferous, he was not prepared to recognize it where only the top 
appears in an unfamiliar stratum. 

The lydite conglomerate corresponds with the black chert bed which 
occupies a similar horizon in the Ta-ning-ho section, and the fauna collected 
by von Richthofen from the beds / and k, and described by Kayser, is 
regarded by Weller as closely related to that which we obtained at Su-kia-pa. 

In this connection it is desirable also to mention certain fossils 
described by Martelli,* collected by the missionary Giuseppe Giraldi in 
the vicinity of "Lean-san," in the Ts'in-ling mountains of southern Shan- 
si. f I have not been able to find the locality "I^an-san" (which may 
perhaps be transliterated Liang-shan, Two Mountains) on any European 
or Chinese map available, but it can not be far from the section observed 
by von Richthofen. Weller regards the fauna collected by Father Giraldi 
as even more nearly related to that from Su-kia-pa than is that described 
by Kayser. 

*Bol. Soc. Geol. Ital., vol. xx, p. 295, Fossili del Siluriano Inferiore dello Schcnsi (Cina), Alessandro 
Martelli. 

t Probably the same as Abbe 1 David's Lean-chan, described by Paul Fischer in Bull, de la Soc. Geol., 
Ser. in, vol. ii t p. 408. 



58 RESEARCH IN CHINA. 

Von Richthofen's section includes Silurian (Gothlandian) strata as 
determined by abundant fossils (beds i and h) and a very meager repre- 
sentation of the Devonian (bed g). The expedition of 1903-04 found no 
certainly Silurian fossils in the Ta-ning-ho section. L6czy, who traversed 
the Kia-ling-kiang just west of von Richthofen's locality, passed in a 
boat and did not observe the Silurian; but at a point somewhat further 
north he obtained a definite observation of the occurrence of the Devonian. 
The locality is in the western Ts'in-ling-shan, in the province of Shen-si, 
at the village of Paj-suj-kiang (Pai-shui-kiang, White Water River). L6czy 
described the occurrence as follows:* 

When we had left a steep terrace [Talstufe] our way entered a narrow ravine, in which 
steep limestone walls rose on both sides almost to Paj-suj-kiang. In this gorge the limon- 
itic sandstone, and the clay shale which is associated with it, is repeatedly exposed wherever 
the arches of the anticlines have been cut through by the action of the river. Above the 
sandstone occur well-bedded, thin, limestone layers, and above these the thick beds of the 
bituminous limestone extend to the high ragged edge of the ravine. 

In the marly strata between the dark-blue limestone layers occur numerous petrified 
remains of shellfish, such as corals, crinoids, brachiopods, fenestellas, and also great heaps 
of shells of a large form of musseL The cross-sections of the latter remind one strikingly 
of those of megalodonts. In the material which was here collected the following species 
were determinable: 

Spirifer, cf. canalifera Valen. Cypricardinia lamellosa Phill. 

Dielasma (cf. sacculus) minimum n. sp. Favosiles cervicornis Goldf. 

Pentamerus brevirostris Phill. Stromatopora sp. indet. 
Megalodon (sp.) v. Pachydomus? sp. 

In Europe these forms are characteristic of the Devonian system. The thin Devonian 
strata pass upward gradually into a thick bituminous limestone; in consequence of this 
relation, because of its extraordinary thickness, and also on account of its analogy with 
the strata which von Richthofen described and definitely determined to be Carboniferous, 
I place this limestone formation in that system. We may therefore conclude, from the 
stratigraphic relations as well as from the conditions of deposition, that, on the southern 
slope of the Shl-ta-shan, the Devonian and Carboniferous occur in an unbroken, continuous 
sequence. 

Our route extended about 14 kilometers upon the strata which I have just described; 
below occurred the carbonaceous sandstone and clay shale; above that bluish limestone 
interbedded with black chert, in the marly layers of which occurred the Devonian fossils, 
and finally uppermost came the Carboniferous limestone, which, with a thickness of about 
400 meters, extended to the tower-like pinnacled divides and ragged cavernous plateau of 
the Shl-ta-shan. 

In the paragraphs preceding the above-quoted description, I<6czy 
gives an account of the rocks immediately below those containing the 
Devonian fossils, describing them as gray ferruginous sandstones, contain- 
ing pyrite and brown iron oxide with interbedded threads of coal. This 

♦Rcisc des Grafen Sz&henyi, vol. i, p. 433. 



WESTWARD TO TIBBT. 59 

description agrees with that of certain portions of the Sin-t'an formation 
observed by our expedition in eastern Ssi-ch'uan, and the position of the 
fossiliferous limestone corresponds with that of the pink limestone in 
which, near Ta-miau-ssi, Blackwelder found the few fossils that are doubt- 
fully referred by Girty to the Devonian or lower Carboniferous. 

On the agreement of the observations of von Richthofen and I*6czy 
and ourselves, we may conclude that throughout northern Ssi'-ch'uan and 
southern Shen-si the Devonian is represented by thin strata of calcareous, 
marly, bituminous character, which nowhere attain very great thickness, 
which may in fact be wanting in some sections, and which are conformable 
to the Silurian (Gothlandian) below and the Carboniferous above. 

In connection with the occurrence of middle Paleozoic fossiliferous 
strata in the western Ts'in-ling-shan it is desirable to consider the for- 
mations of the Hei'-shui series, which were observed by our expedition in 
crossing that range in longitude 108 and which are tentatively assigned to 
the period. They are siliceous argillites of greenish and reddish tints, which 
more nearly resemble the Sin-t'an formation than any other that we know, 
and appear to occur as it does, between a massive limestone below and a 
coal-bearing limestone above. In general terms the stratigraphic similarity 
between this sequence and that of the Paleozoic in the middle Yang-tzi 
region is such that we have little doubt in classing the whole as also Pale- 
ozoic and the slate formation as middle Paleozoic. The slates include 
quartzite and conglomerate at the base and appear to be thicker than 
their supposed equivalents further south. We regard them, therefore, as 
a nearer shore phase, and also recognize that they may include a more 
complete sequence than is found in the Sin-t'an. 

MIDDLE PALEOZOIC STRATA BEYOND CHINA. 

We may next consider the distribution of Devonian strata in northern 
and western Tibet, as determined by Obrutchov, Mushketov, Romano vski, 
Bogdanovitch, and Stoliczka. 

The journey of I*6czy, otherwise so fruitful in geologic details, gives no 
clue to the occurrence of the Devonian in the ranges of northern Tibet. In 
justice to him it must be said that his opportunities for observation were 
limited by the official attitude of the Chinese authorities and the conditions 
attending the expedition to which he was attached. Although he traveled 
during four months within a short distance of the northern base of the 
Nan-shan, he was able to observe the rocks in place only in two locali- 
ties; in the vicinity of Kan-ch6u-fu and south of Su-ch6u. He describes 
strata which he considers to be early Paleozoic, but which, as stated on a 
previous page, are not identified by fossils and probably are of pre-Cambrian 



60 RESEARCH IN CHINA. 

age. His observations are described in the twelfth chapter, volume I, 
of his work, on pages 552 to 559, but need not here be further considered. 

Obrutchov's journeys in northern Tibet were very extended. His 
observations are unfortunately not fully available. The two great volumes, 
Central Asia and Northern China, published in Russian, are in effect an 
orderly transcription of his field-notes, from which it is difficult to obtain 
an idea of geologic relations.* In his preface Obrutchov reserves all con- 
clusions for a third volume, which is not yet available. He has, however, 
found a most able interpreter in Suess, who supplemented the data found 
in the volumes by correspondence with the author. I quote from him. 
The region referred to lies in the heart of Asia, south of the Gobi desert and 
north of the Tibetan plateau, between latitudes 35 and 40 north, and on 
either side of longitude ioo° east. The description includes an account of 
rocks which are both older and younger than middle Paleozoic and in this 
volume are systematically discussed elsewhere, but the quotation is best 
given as a whole. 

Suess says:f 

The width of the Nan-shan, between the northern margin of the Tsai-dam and the 
southern margin of the oasis of Kan-su, is equal to the width of the Alps between Biella 
and Freiburg, and one may say that all the region commonly designated under the name of 
Nan-shan corresponds approximately in extent to the Swiss Alps. The great height of 
the ranges is accompanied, however, by a relatively even more striking altitude of the 
valleys, a circumstance which diminishes the differences of level in the interior of the 
mountainous region, but the observer is even thus below the limit of eternal snow. 

Prom Prevalsky to Roborovsky numerous but hardy observers have contributed to 
knowledge of the topography of this mountainous region, but up to the present time only 
two competent geologists have traversed it. The first was L6czy, whose researches out- 
side of the northern border were strictly limited to the route from Lan-chriu to Liang-ch6u, 
to the valley of Si-ning and the southeastern part of the country. He was followed by 
Obrutchov, who studied several sections across the northern ranges and in a long expedi- 
tion traversed all the chains in the vicinity of their northwestern extremity. Thence, 
following their direction, he reached the field of observation of L6czy, south of the Ku-ku- 
nor, and thereafter, crossing the eastern part of the ranges, regained the oasis of Kan-su. 

After commenting on the reconnaissance character of these investiga- 
tions and the incompleteness of our knowledge, he says : J 

In the meridian of Sti-ch6u four high mountain chains rise between the oasis of 
Kan-su and the longitudinal valley of Ku-ku-nor. They are uniformly directed west- 
northwest. They are: the Richthofen range, the To-lai-shan, the range of Alexander the 
Third, and a fourth chain which is little known and is separated from the preceding by a 

* In examining these volumes I have been greatly assisted by Mr. G. Zon, assistant forester, Bureau of 
Forestry, U. S. Department of Agriculture. 

fLa Pace de la Tern, French edition, 1902; vol. m, part 1, page 231. 
%Ibid. t page 232. 



OBRUTCHOV ON THE NAN-SHAN. 6l 

valley of the Sou-lai-kh6 [Su-lei-ho].* In the continuation of the Alexander mountains 
to the west-northwest, or a little to the south of this line, rises the Ta-siou6-shan [Ta-su6- 
shan, Great Snowy Range]. 

The Richthofen range is 50 to 60 versts across and may be divided into several groups 
of folds, of which the first without doubt exceeds 20,000 feet, 6,000 meters. At the northern 
base, near Tsin-fo-sy, southeast of Sou-tch6ou [Sii-chou], there is a mass of granite, but 
although the granite rises rapidly it does not extend far into the mountains. It is followed 
by a band of upper Carboniferous with beds of coal, inclined to the southwest; then by 
lower Carboniferous with Productus striaius; by a red and green Devonian sandstone; 
and finally by quartzites and limestones which are probably Silurian. Before the first 
summits of the range are attained the beds are already inclined towards the north, and all 
the ridges of the Richthofen range may be considered as closely appressed folds of anal- 
ogous Paleozoic terranes, which are tilted to verticality or overturned toward the south. 
There seem also to be overthrusts. Possibly some of the coal-measures belong to the 
Angara series. At the southernmost divide called the Tsin-pin-ta-pan (14,000 feet, 4,220 
meters) and even above this pass strata of the Gobi series lie in discordance against the 
southern base of the Richthofen mountains; they everywhere dip very steeply toward the 
valley of Khoun-tschoui, which forms the limit of the slope of the To-lai-shan. * * * 

Still further to the west-northwest on the middle course of the Sou-lai-kh6 [Su-lei-ho] 
there occur in the Paleozoic series of the Richthofen mountains red and green sandstones, 
in the midst of which are interbedded layers which contain Devonian fossils (Rhynchonella 
alinensis according to Tschernyschew). Obrutchov mentions in another locality Spirifer 
elegans and Spirifer anosoffi. [Central Asia, 11, pp. 9 and 10.] 

We may here interpolate an extract from Obrutchov's own account :f 

On the southern slope [of the Richthofen range] we see a thick series of supra- 
Carboniferous deposits forming one of the southern ridges, the divide of the range. They 
strike north-northwest diagonally to the range, and dip steeply on both sides. Below the 
peak Yang-k'ou-er appear more ancient formations: gray sandstone and shales slightly 
metamorphosed, which I consider ancient Paleozoic. They do not resemble closely the 
ordinary metamorphic sandstone and schists of the Nan-shan and other parts of central 
Asia. They may be Silurian, or perhaps still older. Fossils have not been found. This 
series is much contorted in various directions, east-northeast, east-west, and west-north- 
west. Apparently it formed the range when the supra-Carboniferous sandstones were 
deposited at its southern base; now it forms the southern slope of the main ridge. The 
remaining part of the Richthofen range represents an enormous anticline, which is over- 
turned southward, and on the limbs is composed of a great thickness, 2,800 to 3,500 feet, 
850 to 1,050 meters, of conglomerates, mostly of red color; in the southern limb they stand 
almost perpendicular and in the northern they dip inward. Near the axis of the fold the 
conglomerates are replaced by red and green sandstones and shales with thin layers of 
conglomerate. These strata apparently form secondary steep folds. The strike is west- 
northwest, parallel to the modern Richthofen range, as might be expected, since the range 
has been formed in its present position by the dislocation of this series. The thickness of 
the conglomerate of the southern limb forms the crest of the mountain chain, with its 



♦The French spelling khe* is a transcription of the Russian xe, pronounced as xo, and rendered in 
English ho, the Chinese for river. 

f Central Asia, Nortlj China, and tfce Nan-shan, vol. n, p. 145, 



62 R8SBARO& IN CHINA. 

steep rocky peaks. The series of red conglomerates underlain with red and green sand- 
stone and shales is most probably pre-Carboniferous. I think it equivalent to the series 
of red and green sandstone with middle Devonian fossils, which I have found in the Richt- 
hofen range considerably further west on the section from the spring A-tza-k'ou to the 
oasis Ch'ou-ma-er (pages 8-10) ; and also in a nearer section, in the canyon of Tsin-fo-ssi, 
east of the meridian of Sii-chou. We shall meet a series of red and green sandstones and 
shales, which underlie Carboniferous limestones with fossils and which form the northern 
ridges of the range ; a similar red conglomerate was seen in the eastern part of the range 
Mo-ma-shan. Hence it is more probable that all these similar formations of the Richt- 
hofen range present shore and shallow water deposits of the same age, namely Devonian. 

Suess continues:* 

The To-lai-shan in the meridian of Sou-tch£ou is a somewhat narrow chain, but 
like the Richthofen range, rises high above the snow-line, of which the altitude is 14,600 to 
15,200 feet, 4,400 to 4,600 meters, in this region. It is distinguished from the preceding 
range by an outcrop of gneiss along its southern border. The attitude of the beds, accord- 
ing to the description of Obrutchov, is very peculiar: after having crossed, in coming 
from the north, the intermontane belt of the deposits of Gobi, one observes intense folding 
in a Paleozoic series, which is very thick. Locally the strike is northeast or north-northeast ; 
then the strata resume the dominant west-northwest orientation, and finally the most 
recent formations, the Carboniferous with beds of coal and Fusulina limestone, rest upon 
the gneiss. The impression which the section gives in this locality is indeed not so much 
that there is an overlap of the upper Carboniferous upon the gneiss as that there is an 
overthrust toward the south, of the entire Paleozoic series upon the gneissic belt. 

Referring to another section of the To-lai-shan, about 50 versts, 53 
kilometers, west-northwest of the firstf Suess describes the continuation of 
the folds which involve Devonian and later Paleozoic strata resting upon 
metamorphic schists; and shows further that the gneissoid zone along the 
southern margin, which has widened considerably, appears to be underlain 
both north and south by upper Carboniferous coal-measures. This struc- 
ture presents a problem of overlap or overthrust which remains indeter- 
minate. 

The range of Alexander the Third rises south of the broad valley of To-lai-kouan, 
which is entirely filled with debris ; it is formed, as may be seen from two transverse 
sections taken a score of versts apart, of lower Paleozoic strata upturned and folded. 
Toward the south these beds pass beneath a great syncline of Carboniferous strata, in 
the midst of which the sandstones above the coal-measures are very extensively developed. 
This synclinorium is so broad that the sandstones overlying the coal-measures constitute a 
series of secondary arches, and the summits of the Ou-j6-chan, the most elevated part 
of the chain, probably consist of them. J 

Obrutchov himself sums up his description of the section of the range 
of Alexander the Third by saying that " To-day's observations show that 

♦La Pace de la Tern, vol. m, p. 234. 
f/Wd, bottom of page 235. 
tlbid., page 236. 



THE WESTERN KUEN-LUNG. 63 

the series of gray schists, quartzites, and limestones, is considered older 
than that of gray, green, and lilac shales, which we take for Devonian." 

These older schists, quartzites, and limestones belong to that series 
which has been considered early Paleozoic, but which I correlate tentatively 
with the late Proterozoic. I shall refer to it again in connection with Pale- 
ozoic di as trophism. 

Having referred briefly to the structure of the fourth chain, which is 
but imperfectly known, but which is undoubtedly formed by beds of 
Paleozoic strata, in part at least, Suess proceeds:* 

The structure of these four ranges of the Nan-shan, from the oasis of Kan-su to the 
vicinity of the valley of Bouk-hafn-gol thus presents the following characteristics: gneiss 
is seen only upon the southern flank of the To-lai-shan; all the rest of the mountainous 
region is formed of closely folded Paleozoic sediments. Near the northern margin there 
are suggestions of an overturn toward the north ; in the interior of the mountains the beds 
appear in a vertical position or exhibit a movement toward the south. The gneissic zone 
is not associated with the lowest strata of the Paleozoic series, as would be expected in the 
normal succession, but instead with the Upper Carboniferous. 

The observations of Obrutchov in the southeastern portion of the Nan- 
shan, as quoted by Suess, show that the pre-Carboniferous Paleozoic strata 
are present in that part of the range. There can be no question but that 
outcrops of Devonian strata extend from the vicinity of Lan-ch6u south- 
eastward along the trend of the mountain chains to southwestern Shen-si, 
in the region where L6czy collected fossils of that period near Paj-suj-kiang. 

Proceeding westward from the Nan-shan range, along the southern 
margin of the Gobi, we have in the western Kuen-lung a section by Bog- 
danovitch across the ranges adjacent to what is known as the Valley of the 
Winds. I again quote Suess :f 

One of the sections which Bogdanovitch observed across the western Kuen-lung 
crosses the Valley of the Winds. Coming from the north the first chain, the Altyn-tagh, 
is formed of Devonian with masses of granite, exactly as in the Russian range which lies 
far to the southwest. The second chain, the Youssoup-alyk-tagh, which follows the Tchi- 
men-tagh, is a broad band of gneiss. The Valley of the Winds corresponds to a Carbon- 
iferous syncline. This section, which somewhat further west is extended southward, first 
comes to the opposite limb of the syncline, then to the steeply inclined Devonian and the 
great granite massif of the Kyzyl-oungoui'n-in-tiour6, beyond which there succeed further 
outcrops of Devonian strata. It is in the region beyond this massif that there rises the 
Ailik-tagh, where Bogdanovitch found at a great altitude "polypiers" of middle Devonian 
age. J 



♦La Face dc la Terre, vol. in, page 237. 
f/WA, page 243. 

J See also Beitrage zur Stratigraphie Zentral Asiens, Suess in Denkschriften der k. Acad, der Wiss., 
Wien, lxi, 1894, p. 435. 



64 RESEARCH IN CHINA. 

Devonian strata are known where the Kuen-lung converges in the 
Mustagata, toward the Tien-shan, and have been identified in the southern 
ranges of that great system, north of the Taklamakan desert. Farther to 
the northeast, in Trans-Baikalia, they constitute the oldest fossiliferous 
rocks known. 

We have thus traced the repeated outcrops of middle Paleozoic strata 
from the province of Shen-si in central China, in longitude 106 east of 
Greenwich, northwest and west to longitude 74 . The terranes probably 
comprise pre-Devonian Paleozoics, at least as far west as longitude 94°, 
but in the section last quoted from Bogdanovitch middle Devonian appears 
to rest directly upon the crystallines. Nevertheless, in the present state of 
geologic knowledge of these remote regions, it would be hazardous to assert 
that earlier Paleozoic, even to Ordovician or Cambrian, is not represented. 
Somewhat farther west, in the Zaravchan (Sarawschan) range, longitude 
70 , Romanovski collected Holy sites catenulatus. The middle Paleozoic 
of eastern Turkestan is closely related to and connected with that of 
Europe by way of the Urals, and also with North America by Siberia.* 

The line of observations which we have followed from Central China 
pursues the course of one of the great mountain trends of Asia, between the 
Gobi and the Tibetan masses. Paleozoic strata may probably be absent 
over part of the latter, at least if the inference based on structural axes be 
valid. Around its eastern end the ranges extend southward toward the 
Malay peninsula, and in Burmah they are joined by the Himalaya trends. t 
We may trace the occurrence of Middle Paleozoic rocks along this southern 
route also. 

Devonian is known from several localities in southwestern Ssi-ch'uan 
and adjacent districts in Yun-nan, among the Paleozoic strata which form 
the mountain ranges of western Tibet, bordering the Mesozoic red basin 
on the west. Westward from Ja-ch6u-fu (latitude 30 , longitude 103 ), in 
the vicinity of "Lin-tschin-shien," L6czy found the Jurassic itself thrown 
into folds, resting unconformably on strata which he assigns in general 
terms to Silurian, i. e. 9 early Paleozoic. He refers to the rocks simply as 
limestone, and makes the correlation without paleontologic evidence. J 
Beneath these strata occur granite and diabase. A few miles further 
west, between the Fu-yung-ho and the village of Hoani-pu (Hua-ling-pu) 
he crossed the Ta-shian-ling, which is composed of granite and quartz 
porphyry and flanked on both sides by coal-bearing Jurassic strata. On 
the northeastern slope the supposed Silurian beds occur. The town of 

* Dc Lapparent: Traitl dc Geologic, 1906, vol. 11, p. 864. 
fSuess: La Pace de la Terre, vot m, map. 
JReise dcs Grafen Szechenyi, vol. 1, p. 677. 



DEVONIAN OF THE SOUTH. 65 

Ni-tou, a short distance to the northwest, lies in a synclinal basin of early 
Paleozoic strata overlain by Rhaetic and Jurassic and flanked by ranges 
of granite and quartz porphyry. In this vicinity, at the village of Hua- 
ling-pu, L6czy observed closely folded shales and dark, bituminous, earthy 
limestones, from which he collected a number of fossils of middle Devonian 
age.* The fossiliferous limestone beds were thin and apparently under- 
lain by sandy shales and gray, half -crystalline limestones, and the presence 
of Silurian strata beneath the Devonian was observed. 

While the fossils collected in this locality leave no question of the pres- 
ence of Devonian strata, the relations which appear to be implied in the 
accompanying diagrams, between the Paleozoics and the adjacent granites, 
are not at all clear. One would infer that the granites were pre-Paleozoic ; 
on the other hand the descriptions suggest that they may be intrusives 
and of post-Paleozoic age. 

In northern Yun-nan, in latitude 28 , longitude 104 , is the celebrated 
locality of Ta-kuan-ting, from which von Richthofen obtained the rich 
collection described by Kayser.f Von Richthofen did not himself collect 
the fossils, but purchased them in the province of Ssi'-ch'uan, whither they 
are brought in great numbers as medicinal charms. 

La Touche and Datta determined the presence of Devonian strata in 
the northern Shan states, where they found a full and characteristic fauna. 
The presence of the Silurian rocks is probable, but not determined. J 

The most recent and complete account of the Ordovician and Silurian 
and Devonian in the Himalayas is that given by Hayden.§ He describes 
650 feet, 195 meters, of strata, comprising shaly sandstones at the base 
(150 feet, 45 meters), shaly, dolomitic, and siliceous limestones (420 feet, 125 
meters) among which six divisions are distinguished, and reddish quartz- 
ite (80 feet, 24 meters) ; the last is followed by the unfossiliferous white 
Muth quartzite. The strata have yielded fossils ranging from Caradoc to 
Llandovery or Wenlock, and therefore corresponding in general position 
with the beds of middle Ordovician and Silurian age in central China. The 
white Muth quartzite passes upward into siliceous limestone, which is con- 
sidered to be Devonian, and Devonian strata are probably present through- 
out the Himalayas, although of very moderate thickness. The western 
extension of this series along the ranges of western Asia to the Caucasus is 
not clearly made out, but is most probable. || 

♦Reise des Grafen Szechenyi, vol. 1, p. 682. 

t China, vol. rv, p. 76. 

JNoetling: Gen. Report G. S. I., 1900. 

§ Memoirs G. S. I., vol. xxxvi, part 1, pp. 24-27, 1904. 

|| De Lapparent: Traite* de Geologic, 1906, vol. n, p. 812. 



66 RESEARCH IN CHINA. 

These notes suffice to trace the marine connection of Central China 
with Europe by a route south of the Tibetan plateau region, and thus to 
bring out the fact that the interior sea of Asia, the Tethys, during middle 
Paleozoic time completely surrounded the plateau region, which was prob- 
ably a land area. 

MIDDLE PALEOZOIC DIASTROPHISM. 

Diastrophic movements in China during the middle Paleozoic were 
very slight. As has been brought out in discussing the sedimentation 
of the Silurian and Devonian periods, there was no considerable deposition 
of marine sediment, no evident accumulation of continental deposits, no 
notable depth of erosion. A stable condition of the southeastern conti- 
nental masses is plainly indicated. 

A similar inference holds for Gondwana Land in the peninsula of India 
and the Tibetan mass, so far as we may draw one from the meager sedi- 
mentation that represents Silurian (Gothlandian) and Devonian in the 
Himalayas : a few hundred feet of limestone and quartzite ; the lands were 
not high. 

A somewhat different suggestion lies in the Devonian and Silurian (?) 
deposits of northern Tibet, which Obrutchov, the explorer of the Nan-shan 
system, describes as quartzites and shales of great thickness. They appear 
to represent an epoch of vigorous denudation, and their volume seems to 
stand for an elevation equivalent to a mountain range. According to 
Bogdanovitch, there is an overlap of middle and upper Devonian onto 
an eroded surface which exposes granite; the elevation had, therefore, by 
middle Devonian time, given place to peneplanation and subsidence; he 
regards this invasion of the sea as an event of prime importance and 
designates it the Kuen-lung transgression. 

It is not clear what the nature of the elevation was: an orogenic 
movement, perhaps accompanied by granitic intrusion, or an upwarp 
without folding or visible intrusion? Comparison with the Taconic dis- 
turbance in New England or the Caledonian movement in Scotland, both 
during Silurian time, tempts speculation to postulate a similar orogenic 
event in central Asia; but the conservative position taken by Suess* in 
deferring a correlation of these events is the sound one in the limited state 
of knowledge. This attitude is the more reasonable because the Taconic 
and Caledonian disturbances are geographically and presumably causally 
related to the Atlantic basin, whereas the region in central Asia belongs to 
a distinct continental province. 

♦ Bcitragc zur Stratigraphie Zentral Asiens, in Denkschriften der k. Akad. Wiss., ui, 1894, p. 435. 



AN UNCONFORMITY BY EROSION. 67 

PRE-CARBONIFEROUS UNCONFORMITY. 

Throughout northeastern China, in the provinces of Chi'-li, Shan-si, 
Shantung, and Ho-nan, there is an unconformity which brings the Ordo- 
vician in contact with the Carboniferous. Wherever it has been seen the 
underlying terrane consists of the upper Sinian (lower Ordovician) lime- 
stone; whereas the overlying strata are shales which lie a hundred feet or 
so below beds that carry upper Carboniferous fossils, either marine shells 
or plant remains. The hiatus appears, therefore, to represent later Ordovi- 
cian, Silurian, Devonian, and lower Carboniferous times. 

Local observations all agree that the Ordovician and Carboniferous 
strata are strictly conformable ; so closely parallel are they that von Richt- 
hofen, who repeatedly saw the contact, assumed that they formed an 
unbroken sequence, and characterized the Sinian limestone as Kohlenkalk. 
He did not find any of the sparsely distributed fossils, by which its age has 
since been determined by Lorenz and ourselves, and his error is one which 
sprang naturally from the fact that he had previously observed a massive 
Carboniferous limestone in South China. It follows from the conformity 
of dip over several hundred square miles that the region in question was not 
subjected to disturbing influences during the periods represented. The 
Sinian strata were not folded ; neither, during all this time, were they raised 
to an elevation at which they might have been deeply eroded. 

Apart from the fact that the strata above and below the plane of 
unconformity are identified by fossils and the existence of a hiatus is thus 
proved, the contact itself shows evidences of erosion. The Sinian limestone 
is deeply fissured and cavernous. The cavities show waterworn or corroded 
surfaces, commonly found in limestones exposed to meteoric waters. These 
cavities are filled with bright-colored clays, which owe their varied hues to 
the oxidation and hydration of the iron which they contain. Bog-iron ore, 
sufficient in quantity to be mined, and calcareous tufa are found at the 
contacts. 

The significance of these facts has been discussed in connection with the 
consideration of post-Sinian diastrophism. For detailed descriptions of the 
unconformity as we saw it, reference may be made to volume 1, pages 48 
and 147. In describing the coal-field of Po-shan in northern Shan-tung, 
von Richthofen* states with reference to the Kohlenkalk (Sinian lime- 
stone) that he found no fossils, but noted that in contrast to similar lime- 
stones in other regions it contained no chert. This distinction is one in 
which the Sinian differs from the Carboniferous limestone of southern 
China. 



* China, vol. n t p. 203. 



^.K:;-EAIi-:/H iN ■'EILIJA 




hvVr ihiiiiui f/if 



CHAPTER V — LATE PALEOZOIC 



CARBONIFEROUS STRATA. 

The Carboniferous strata of China constitute two very distinct series, 
both of which are, however, apparently of upper Carboniferous (Pennsyl- 
vanian) age. The one is a sequence of essentially continental deposits: 
sandstone and shales, with numerous coal-beds and occasional thin bitu- 
minous limestones. Many of these strata are no doubt marine, the lime- 
stones in particular being characterized by marine fossils; but many others 
belong to a coastal plain and are either seashore or fluviatile or marsh 
deposits. In China they extend over the northern provinces, Liau-tung, 
Chi-li, Shan-tung, and Shan-si, and there is probably a large peninsula in 
the province of Hu-nan. Beyond China they are of general occurrence 
in the ranges of Mongolia and Tibet, which rise through the great mantle 
of desert deposits. 

The other series is in fact a great single formation, a limestone which 
in some places is more than 4,000 feet, 1,200 meters, thick and is charac- 
terized by marine fossils throughout. It has been identified south of the 
Ts'in-ling-shan in the provinces of Shen-si, Ssi'-ch'uan, and Hu-pe'i, and 
further east along the Yang-tzi-kiang in An-hui and Kiang-si. It occurs 
in the Kuen-lung and Nan-shan mountains of Tibet, and also in the Tten- 
shan in Turkestan. It is furthermore a wide-spread formation throughout 
all of southwestern China, Burmah, and the Malay peninsula. The marine 
deposits are also extensively represented in the Himalayas. 

I first take up the account of the marine formations, which conform- 
ably succeed the Devonian, and next the interbedded continental and 
marine formations which rest unconformably upon older rocks. 

MARINE CARBONIFEROUS. 

The first description of the Carboniferous limestone of southern China 
was furnished by von Richthofen, who gave it the name of the Ki-tau 
limestone, from a locality on the Yang-tzi-kiang. His description has 
been given in connection with his account of the Devonian of the same 
region. 

Three hundred and seventy miles, 600 kilometers, west of von Richt- 
hofen 's locality, in the gorges of the Yang-tzi-kiang, between I-chang and 

71 



72 RESEARCH IN CHINA. 

Wu-shan-hi£n, the Carboniferous limestone is beautifully exposed. Its 
distribution is shown on the geological map of the Yang-tz'i gorges, plate 
xxxvi of volume i of this report. It was also repeatedly crossed in the 
sections on the Ta-ning-ho in eastern Ssi-ch'uan, and its relation to the 
underlying strata was thus repeatedly observed by the members of the 
expedition of 1903-04. The greenish, sandy, and bituminous shales of the 
middle Paleozoic are followed by calcareous shales, and these by massive 
gray limestones in which layers and nodules of black flint constitute a 
conspicuous feature. A pink limestone at the top of middle Paleozoic 
strata yielded a few fossils already referred to and described in volumes 
1 and in of this report. They are not earlier than Silurian (Gothlandian) , 
may probably be Devonian, and may even be as late as the lower Carbon- 
iferous (Mississippian) . This fauna has nothing in common with that from 
the base of the gray limestones which closely overlie it, and it is evident 
that the life conditions underwent a notable change between the two epochs. 
Nevertheless there is such a uniformity of sequence in repeated sections 
that the strata can not be otherwise described than as conformable. We 
are thus led to conclude that in this district the sequence of deposits 
which began with the lower Cambrian (Sinian) limestone, and continued 
conformably through the middle Paleozoic, remained unbroken through the 
lower, middle, and upper Carboniferous. Yet it is to be noted that the 
sedimentation from late Ordovician to upper Carboniferous time was very 
meager and may possibly have ceased altogether at intervals in the middle 
Paleozoic. 

This upper Carboniferous limestone, which we distinguished by the 
name Wu-shan from its prominent section in the Wu-shan gorge of the 
Yang-tzi, is probably the same as the Ki-tau limestone of von Richthofen. 
But until the faunas have been more fully collected and the geology of the 
entire region more accurately mapped, it is as well that they should be 
designated by separate names. 

The Wu-shan limestone exhibits a sequence which has been described 
by Blackwelder in volume 1, p. 275. 

In the district in central China which has just been described we have, 
so far as the faunal evidence goes, a large development of the upper Car- 
boniferous and only a very meager representation, if any, of lower Carbon- 
iferous strata. But from this locality toward the northwest and southwest 
Carboniferous limestones may be traced through the observations of von 
Richthofen, L6czy, Obrutchov, and others, and they are apparently not 
restricted to the upper Carboniferous. De Lapparent gives a good synop- 
sis* of the occurrence of the older Carboniferous strata. In view of the 



♦Traits de Geologie, fifth edition, 1906, p. 914. 



CARBONIFEROUS IN GENERAL. 73 

very meager collections which have been obtained it is, however, hardly 
worth while to attempt to distinguish the different horizons of the great 
limestone formation in the light of present knowledge. And therefore, in 
describing its distribution I shall refer simply to the Carboniferous, which 
may include both lower and upper or either one of them. 

Northwestward from the Yang-tzi gorges Carboniferous limestone is 
known to form conspicuous ranges in northeastern Ssi'-ch'uan and southern 
Shen-si,* and through the work of Obrutchovf and L6czyJ it has been traced 
into northeastern Tibet, where it is more particularly represented in the 
southern mountain chains of the Nan-shan. In the section observed by 
L6czy near Paj-suj-kiang the transition from fossiliferous Devonian strata 
to the gray Carboniferous limestone is accurately described as one of strict 
conformity, and this is also true of the sections given by von Richthofen 
in the same district of northern Ssi'-ch'uan. The formation in this district 
might readily be confused with a similar limestone of Permian age, which 
rests unconformably on the folded Paleozoics. 

The expedition of 1903-04 found the Carboniferous limestone and argil, 
lite constituting a recognizable terrane in the valley of the Han above Hing- 
an-fu and in the Ts'in-ling-shan, in longitude 108 east. The characteristic 
rocks are highly carbonaceous; they vary from limestone and quartzite 
to black slate. Their Carboniferous age is not determined by fossils, as 
they are more or less metamorphosed, but it is inferred with confidence on 
the basis of their commonly carbonaceous character and their stratigraphic 
relations. § 

The relations of the Carboniferous limestone to older rocks in northern 
Tibet are not clearly expressed in the available literature. Such a section 
as that of Obrutchov's of the Richthofen range|| is indefinite. The Car- 
boniferous is represented as lying between folded masses of rocks that are 
questionably assigned to the Silurian, it resting unconformably upon the 
one mass and being overthrust by another. The structure itself is unusual, 
as it is delineated, and the age of the Silurian rocks being doubtful it is 
not possible to say what the unconformity means. If the older strata are 
those of the Nan-shan sandstone and belong to the latest pre-Cambrian 
(Hu-t'o) system, as has been suggested in the chapter on that subject, 
the Carboniferous in this northern range overlaps upon pre-Paleozoic 

* China, vol. n, p. 599. 

t Central Asia and the Nan-shan Mountains, Obrutchov, vol. n, p. 356, pi. n (in Russian). Also, La 
Face de la Terre, E. Suess, vol. ni, p. 271. 

{Retse des Grafen Szechenyi, vol. 1, p. 433. 

f See chapter on the Han province, vol. 1, p. 300. 

H Central Asia and the Nan-shan Mountains, vol. n, p. 164, fig. 130. Also La Pace de la Terre, Suets, 
vol. in, p. 232. 



76 RESEARCH IN CHINA. 

(cb) Dark coal-bearing shale, with slickens covered with calcite. The thickness of 
this bed could not be estimated closely on account of loose stuff on the slope, but I could 
see by the position of the tunnels that below this shale occurred 

(cc) the principal coal-bed. From the height of the slope the thickness of cb and cc 
may be estimated at 18 to 20 meters. 

(d) Dark or black bituminous clay marls, with fine calcite veins and full of fossils; 
including also yellowish-gray layers of mussel shells. I saw these only on the dumps; the 
thid™*^ is therefore unknown, and I can only infer that they occur below the coal-bed. 

(e) Gray, bituminous, marly limestone, which occurs on the southern slope from the 
mines and in the foot of the principal mine ; which alternates with thin layers of coal, and 
which is full of fossils. 

(/) Yellow sandstone, colored with iron hydroxide and in part shaly. 

The thickness of the strata included from d to / is uncertain, as the base of / was not 
visible ; but all the strata seen on the southern side of the basin lie unconformably on the 
Nan-shan sandstone, which dips steeply toward the south. 

L6czy gives a list of fossils which serve to correlate the strata with the 
Russian Upper Carboniferous (Mjatschkowo) . 

There are many references in the works of Obrutchov to coal-bearing 
strata in Mongolia and the Nan-shan. In some cases they are identified 
as Carboniferous, and in others as supra-Carboniferous. The conditions 
which prevailed in Shan-si were general throughout central Asia north 
of the Tibetan arm of the Tethys, and the deposition of continental deposits 
containing coal, yet interbedded with occasional marine limestones, was 
wide-spread. The area thus characterized reached into Turkestan on the 
west, perhaps, as far as longitude 8o° east, but was bounded by a sea on the 
northwest, where the Carboniferous limestone of the Ti£n-shan mountain 
system was being deposited. 



PSSEAftfH IN fHTMA 




Siiiiihfni Axiti •lurimi 



Chapter vl— permo-MESOZOIG 



TRANSITION FROM PALEOZOIC TO MESOZOIC' 

Theoretical considerations. — There is no sharp plane of division to be 
discovered between the Paleozoic and Mesozoic in Asia. In some dis- 
tricts there was transition of sediment and of faunas; elsewhere, during 
equivalent time, there is disturbance of physical or biological conditions. 
In one place a decided change of sediment, in another an equally abrupt 
change of fauna, in a third an unconformity of dip between beds that 
differ in kind and in fossils : these may be taken as local dividing planes ; 
but they do not range themselves into one horizon. They fall anywhere 
within the later Carboniferous, or within the Permian, or Trias. It is 
in the nature of things that a great transformation of features, climates, 
and faunas, such as characterized the passage from the period of the Old 
Life to that of the Middle Life, should take time, and that the evidences 
of change should appear at different geologic moments in different places. 
The better to understand the facts which are presently to be listed, we 
may review briefly the theoretical sequence of events. 

The leading fact that distinguishes the early Mesozoic from the late 
Paleozoic is the contrast in the extent of the lands, which, through with- 
drawal of the epicontinental seas, became relatively very wide. This change 
theoretically resulted from enlargement of the ocean basins by subsidence 
and widening, which was associated with protuberance of the continents 
and local deformation of rocks by folding.* 

There is no question about the leading fact, of which Asia, as well as 
North America, offers a striking illustration. The wide seas of the late 
Carboniferous shrank, in the Permian and Triassic, to embayments around 
continental platforms. One effect of that shrinking was interference of 
emerging lands with circulation of marine currents. Hence followed 
climatic differentiation and contrasts of warm and cold currents in the seas 
and sharper contrasts of climatic zones on lands. A further effect of these 
changes was the development of new species and extinction of organisms 
incident to altered conditions of habitat. Faunal change was evidently a 
late effect, since it was sequential upon the others. Do these phenomena 
afford any precise datum that might serve to distinguish a definite epoch, 

* Geology, Chamberlin and Salisbury, vol. u, p. 656. 

77 



78 RESEARCH IN CHINA. 

as the last of the Paleozoic or the first of the Mesozoic, an epoch that could 
be fixed upon as contemporaneous throughout several continents, or even 
within one extensive continent ? It does not appear that they do. 

Granting that deepening of sea basins would withdraw the continental 
seas simultaneously if the continents stood fast, it is evident that the lands 
would emerge soon in one area and only much later in another if the conti- 
nents were here rising and there sinking, as was the case. The effects of 
emergence, i. e., erosion or continental aggradation, were therefore not even 
approximately contemporaneous, for we must bear in mind that earth 
movements are slow. Denudation and aggradation were among the earliest 
processes to become active and the longest to continue. Among the Asiatic 
effects are: that eroded surface which uncovers strata ranging from the 
Carboniferous down to the Silurian in the western Himalayas;* or those 
extensive continental deposits of red cross-bedded sandstones and associated 
shales, which in North China conformably overlie the Upper Carboniferous 
coal-measures. 

The differentiation of local climates from the preexisting conditions 
of a general, somewhat uniform climate may reasonably be compared with 
similar changes during the Pliocene and Pleistocene, following upon the gen- 
eral mildness of the Tertiary. The Paleozoic-Mesozoic transition presents 
even more remarkable extremes, such as the wide occurrence and persistence 
of the Gondwana flora and the development of centers of glaciation in 
India and Australia.! Regarded as an effect of refrigeration and aridity, 
the formation of iron oxide in quantity can not have been an immediate 
result ; geographic and meteorologic changes had progressed notably before 
the deposition of red rocks could have become general. 

Marine organisms, evolving in ocean waters (that in contrast to air 
constitute a medium which is extremely conservative in maintaining the 
conditions of life) are long protected against change and also very sensitive 
to change, especially of temperature. Thus it is not surprising that in 
some ocean currents where the mildness of Carboniferous seas was main- 
tained, Paleozoic forms should have lived on, even after their habitat had 
been invaded by Mesozoic types, as witness the Productus limestone of 
India; or that elsewhere, on the diversion of warm waters and occupation 
of their territory by chillier ones, there should be speedy extinction, even 
of a whole fauna. Even though the endurance of the adult be consider- 
able, that of the larva is very slight, and the latter is the critical factor. 
When we thus consider the physical conditions which permit or limit the 
existence of species, the value of fossils as evidence of contemporaneity is 

♦Hayden: Memoirs Geological Survey of India, xxxvi, pt. i, p. 52. 

t Textbook of Geology, A. Gettrie, vol. n, pp. 1058, 1079, and numerous references there given. 



CORRELATION AND UNCONFORMITY. 79 

qualified by the geographic phase during which the organisms lived. In 
the world-wide Carboniferous seas marine organisms attained cosmopolitan 
distribution; and correlation between Europe, Asia, and America rests 
upon a firm paleontologic basis ; but when those seas, so far as their epi- 
continental parts were concerned, became transformed into bays, straits, 
carribbeans, and mediterraneans, organisms met with great variety of expe- 
rience. Where favored they persisted or slowly evolved ; where adversely 
conditioned they died out or varied, and cosmopolitan relationships gave 
place to provincial diversity. That they did so sooner here and later 
there, and that the old sometimes returned to a habitat from which it 
had been driven during a temporary unfavorable condition, is the record of 
stratigraphy and paleontology.* It follows that correlations on a paleon- 
tologic basis are less reliable during the transition from Paleozoic to Meso- 
zoic than during those periods of more general conditions which preceded 
and followed; and that even though Permian and Triassic faunas were 
more abundant and better known than they are in Asia, we should still 
have difficulty in establishing a plane with reference to which, in central 
Asia, China, Australia, and India, we could say: that which is beneath is 
Paleozoic and that which is above is Mesozoic. There is no such general 
plane. 

Unconformity is a condition common to a transition stage, regarding 
which a word is necessary in explanation of the diversities which Chinese 
sections present. The term covers a great range of phenomena indicating 
discontinuity of deposition, from that which may result from n on deposi- 
tion, marine scour, or subaerial erosion, without obvious disturbance, to the 
most striking differences of structure. We are apt to think of a submerged 
surface as one subject to sedimentation, or vice versa of a surface which 
has not received sediment as one which must have been above water; but 
the inference is not valid in view of the fact that marine currents, when 
confined in straits or shallows to such an extent that the water next the 
bottom moves, are capable of carrying sediment past a district, or even of 
scouring the bottom. Considering the work of corrasion done by rivers 
whose depth and bottom pressure are relatively insignificant, the capacity 
of marine currents to scour can not be questioned, provided the waters are 
equipped with abrading materials in the form of silt, fine sand, or siliceous 
spicules, f Nondeposition during an indefinite time or corrasion of an 
undisturbed stratum may result. It is thus that we may explain the 
contrast of strata where the Carboniferous limestone is concordantly over- 
lain by red terrigenous deposits, as in eastern Ssi-cb'uan. The limestone 

* Williams: Devonian Section of Ithaca, New York, Journal of Geology, vol. xv, p. m, October, 1906. 
t Agassiz: Three Cruises of the Blake, vol 1, pp. 136-139. 



80 RESEARCH IN CHINA. 

which, after the manner of lime deposits, presumably hardened in course 
of accumulating, may be supposed to have been swept clean in a shallow- 
ing gulf or strait until the current was checked and the terrigenous sedi- 
ments from nearby land were laid down. It is evident that the strata 
in contact with the limestone may be nearly continuous with it or indefi- 
nitely younger than it. 

On the other hand, apparently at the other extreme of unconformity, 
we have strata extended across eroded folds, with marked discordance of 
dip. In a case described by von Richthofen and L6czy near Kuan-yuan- 
hidn in northeastern Ssi-ch'uan, erosion has laid bare Silurian strata on an 
anticline including several thousand feet of Paleozoics, and the overlapping 
formation is possibly Permian, more probably Triassic limestone. There is 
no doubt of folding, which resulted in a more or less elevated range, accom- 
panied by erosion which reduced that range to a peneplain. The obscure 
feature is the answer to the question: how does the unconformity consist 
with the fact that in nearly adjacent regions strata are concordant in dip, 
from Carboniferous to Jurassic; such being the case on the middle Yang- 
tzi, in eastern Ssi'-ch'uan, 200 miles, 320 kilometers, distant.* I take it that 
the phenomena illustrate two things which are by no means peculiar to 
Central China. The first is that effects of folding are localized in linear belts 
and may be very decided in certain zones which lie adjacent to others that 
do not share in the disturbance; which remain, for instance, the bottoms 
of deep synclinoria. And the other is that the growth and wasting of an 
elevation due to folding takes no longer than the transition period from 
Paleozoic to Mesozoic. How long that was it is difficult to say, but in geo- 
logic terms it included the latest Carboniferous, the Permian, and part of 
the Trias, in Asia; and probably exceeded Pliocene and Pleistocene time, 
judging by the effects of mountain growth and planation. 

PERMO-TRIASSIC STRATA. 

Angara series. — There are in Asia two series of continental deposits 
which are approximately contemporaneous, but are geographically distinct. 
They both include members which range in age from Permian to Lower 
Jurassic, and thus cover the Paleozoic-Mesozoic transition period. The one 
is the well-known Gondwana series of the Indian peninsula, the other the 
Angara series of Siberia and the Altai region.! Representatives of the 
Gondwana series have been identified in Indo-China and also in Australia. 
These districts lie south of the great central mediterranean of Asia, to which 
Suess has given the name of Tethys, whereas the occurrences of the Angara 

* Research in China, vol. i, chapter xiii, pp. 285 et seq. 
t La Face de la Terre, Suess, vol. ni, p. 27. 



PERMO-MESOZOIC. 8 1 

series lie north of that sea, on the continent of Angara. It is probable 
that the continental area extended from the Gobi region of central Asia, 
eastward to the present coast line or beyond it, and southward beyond the 
site of the Ts'in-ling-shan, south of which it was bounded by the Tethys. 
We thus place in the Angara series the terranes which are about to be 
described. 

Strata which are assigned provisionally to horizons ranging from Per- 
mian to Rhaetic, inclusive, are widely distributed in China, from Shan-tung 
on the east to Mongolia on the west and from Shan-si in the north to Indo- 
China in the south. The identification of the coal-bearing series as Rhaetic 
rests on fossil plants and is usually qualified by an alternative assignment 
to Lower Jurassic. Without attempting to prejudge the definite correla- 
tion these formations are discussed in this section. 

In central Shan-tung observations by the expedition of 1903-04 with 
reference to Permo-Triassic strata were made in the vicinity of Lai-wu-hi^n, 
and are described in volume 1, in the chapter on stratigraphy under the 
Sin-t'an District. They are much less complete than is desirable, since our 
attention was given chiefly to the older rocks, and in the sections which we 
could conveniently observe there were gaps covered by alluvium at those 
points where we should expect the passage from known Carboniferous to 
supposed Permian. Carboniferous beds, identified by marine fossils in a 
bituminous limestone interbedded in the coal-bearing sandstones and shales, 
were followed by red cross-bedded sandstones. On account of their color 
we have regarded the latter as Permian, and we take them to be of fluvia- 
tile origin. Succeeding these, but in interrupted succession, occur red, black, 
and greenish shales interbedded with basaltic flows. There is abundant 
evidence that throughout an area including practically all the central part 
of Shan-tung there was a volcanic district from which eruptions were 
numerous and extensive. The activity began probably during the latest 
Paleozoic and continued well into the Mesozoic. In volume 1 these vol- 
canics have been classed with the Carboniferous, that systematic term 
being extended to cover the Permian. 

Overlying the volcanic series near Yen-chuang, Shan-tung, occur beds 
designated by us as the Sin-t'ai series, and by von Richthofen and Lorenz 
assigned to the Jurassic. In the Sin-t'ai area they are exposed with a 
thickness of several thousand feet, as gray to red sandstones and shales 
with thin beds of conglomerate. Von Richthofen included with them the 
adjoining coal-bearing rocks of Ts'ai-kia-chuang (" Tsing-ko-tschwang ") , 
but on the evidence of the plants collected Schenck placed the coal-measures 
of that locality in the Carboniferous. 

In the coal basin of Wei-hi6n von Richthofen observed the occurrence 
of coal-beds in close proximity to granite, an exceptional relation, since 



82 RESEARCH IN CHINA. 

the deposits he had seen previously were in strata conformable to his 
Kohlenkalk (Sinian). Those were, however, of Carboniferous age, whereas 
these may probably be of Lower Jurassic, according to plants collected by 
Lorenz and described by Potonie. 

Throughout northwestern China, from the eastern outcrops of the Car- 
boniferous coal-measures west of Peking and the western margin of the great 
plains, the area of red and yellow sandstones overlying the coal-measures is 
very extensive. Von Richthofen called these strata ' ' Ueberkohlensand- 
steine" or "Plateauschichten," on account of their relation to the coal- 
measures, their indeterminate age, and their occurrence in the extensive 
synclinoria which form the elevated districts of Shan-si. He gives but 
one section,* in which he distinguishes from below upward the following 
members: 

(i) Sandstone and shale of the coal-measures with several small coal-beds. 

(2) The principal anthracite bed which is accompanied by black slates. 

(3) A series of mostly dark shales and soft yellow sandstones. 

(4) Reddish yellow clayey shales with occasional thin sandstone layers. 

(5) Green and red shales, which are very thin-bedded and hard and break up into 
fine debris. These are interbedded with some thin sandstones which form benches. 

(6) Soft and also hard sandstones, heavily bedded ; 100 feet thick. 

(7) Bright-colored shales like those in 5, which also alternate with a few sandstone 
beds. The principal colors are green, gray, blue, and red; thickness, 120 feet. 

(8) Firm sandstones of a greenish color, very evenly bedded with white mica ; in part 
containing quartz grains as large as peas, which also occur of still larger size and form 
solid conglomerates. 

(9) Shales and sandstones of dominantly red color. 

The last member is probably not the top of the series, the total thick- 
ness of which is estimated at 3,000 feet, whereas that of the underlying 
coal-measures (which are included in the preceding section) is said to vary 
from 400 to 600 feet.t 

At Ta-tung-fu, northern Shan-si, J is a sequence of strata which is 
peculiar not only in being remote from other similar basins, but in the 
great thickness of strata and of the individual coal-beds. Von Richthofen 
describes it as follows : 

Lower Jura; coarse quartzose sandstones with clayey matrix, interbedded with white 
strata of tripoli and also of siliceous calcareous formation, both containing remains of plant 
stems; also coal-beds, which are associated with black shales. The visible thickness is 
1,200 feet. The character and color of the strata vary continually. The strike is north 
30° east, the dip is in a direction north 6o° west, at first at an angle of 40 , which lessens 
to io°, and the upper beds lie almost flat. 



♦China, Tol. n, pp. 414-415. 

f/Wrf., page 453- 

tlbid., vol. n, pp. 35^-359- 



LOWER YANG-TZI. 83 

The strata below the Jurassic are Sinian, and the relation is no doubt 
one of unconformity by erosion, but the stratification is approximately 
parallel in the Sinian and Jurassic beds, and the contact was not seen in the 
section described in the above quotation. In an adjoining section, however, 
near "Hei'-ku-tsze,"* the unconformable contact of the two series was 
observed and is represented in the diagrammatic section as one of uncon- 
formity of dip as well as of erosion. 

CENTRAL CHINA. 

Under this head I consider the occurrence of Permo-Mesozoic strata 
along the Yang-tzi, in the Ts'in-ling-shan, and in the Red Basin of Ssi-ch'uan. 

I begin the enumeration of the known occurrences with that which is at 
once the most eastern and also the first recorded, the deposits in the valleys 
adjacent to the Yang-tzi, between Han-kow and Nan-king, as described by 
von Richthofen, who says:f 

Sanghu sandstone and conglomerate. — The deposition of the Kitau limestone ended 
with a considerable disturbance, as the next formation follows quite unconformably. It 
consists of a quartzose sandstone and quartzose conglomerate, interstratified with thick 
layers of red clay, and carries a coal-bed at a place sixty miles below Hankau. Black 
shales, which overlie the coal, carry some remains of plants. I was unable to establish 
the thickness of this formation. 

Commencement of the outbreaks of porphyry. — The porphyritic eruptions have probably 
continued in China during a long period while sediments were contemporaneously deposited. 
Pumpelly was the first to direct attention to these wide-spread events. But it is only in the 
great granitic region of the eastern coast, between Ning-po and Hongkong, that porphyry 
itself arrives at an extraordinary development. The Chusan islands are almost exclusively 
composed of quartzose porphyry and its tufas, and from there southward it appears to be 
only subordinate in quantity to the granite. I know it from my own observations on the 
island of Hong-kong, and by inference from the observations of others of the region between 
that island and Ning-po. This is the most extensive development of porphyry known in 
any part of the world. 

Deposits of porphyritic tufa, sandstones, and clays. — The porphyries themselves are 
little developed on the lower Yang-tze. I noticed their first appearance in certain porphy- 
ritic tufas which overlie somewhat unconformably the Sanghu sandstone. The latter 
appears, indeed, from its purely siliceous character, to have been antecedent to any out- 
break of porphyry, while the soft and impure nature of all subsequent deposits goes to show 
that they were the tufaceous sediments of eruptions in remote regions. The visible thick- 
ness of this formation below Hankau is about 3,500 feet. It incloses a few beds of coal 
of subordinate value. 

Herewith ends on the Yang-tze the series of ancient formations. 

It will be observed that von Richthofen gives no clue to the age of these 
deposits, which, in view of the unconformity at their base, probably do not 
include the earlier transition sediments, but may comprise the Triassic and 

* China, vol. n, p. 368. 

t American Academy Arts and Sciences, vol. vm, 1869, p. 117. 



84 RESEARCH IN CHINA. 

also the Lower Jurassic. The Sang-hu is thus probably nearly equivalent 
to the Kui-ch6u series. 

On the Yang-tzi still, but several hundred miles further west, occur the 
exposures of Permo-Mesozoic strata which form the foothills along the moun- 
tains of western Hu-pei. Pumpelly described them as he saw them near 
I-chang, and his account is given in volume i, p. 278, of this report. Vogel- 
sang* repeatedly refers to them as being observed in a trip from I-chang 
northward as far as the 32d parallel, from which he returned via Chu- 
shan and the Ta-ning-ho; the latter part of his route coincides with that 
subsequently followed by our expedition. 

We observed strata above the Upper Carboniferous (Wu-shan) lime- 
stone in numerous sections on the Ta-ning-ho and Yang-tzi-kiang, but 
did not examine them closely. There was great uniformity of stratification 
and, despite the marked difference between the massive limestone and the 
red shales which followed it, seemingly perfect conformity of dip between 
the two. Both in the field and since, I have regarded the relations as those 
which result from marine scour by shallowing waters. The limestone, 
having accumulated and hardened beneath waters which were deep enough 
to permit sediments to gather, was swept clean by a current which flowed 
across it, possibly with accelerated velocity, while the waters shallowed; 
and ultimately, in consequence of continued shallowing, the current was 
checked or diverted and red terrigenous deposits were laid down on the 
scoured surface. This sequence implies the nearness of land areas and 
possibly of subaerial erosion of the Wu-shan limestone in adjacent areas 
to a degree consistent with the occurrence of such conglomerate of flints 
as we observed in the float of the Ta-ning-ho. t 

In the limestone, 400 feet, 120 meters, above the base of the red series, 
occur fossils which Girty refers to the late Paleozoic, but with doubt 4 He 
says: 

The evidence upon which the horizon in question is referred to the Paleozoic con- 
sists of the septiferous Terebratuloid, the round crinoid stems, and the general Paleozoic 
complexion of the meager fauna. It is inconclusive and may not stand against any facts 
which strongly point to a Mesozoic age. For this reason my assignment to the Carbonif- 
erous is provisional merely, and should the necessity arise of changing to a younger period, 
the readjustment would entail no serious conflict of evidence. 

Girty 's conclusion from the fossils is in accord with the stratigraphic 
evidence that deposition was more nearly continuous here than in areas 
adjacent on the north and west. The episode of marine scour, which is 

♦Reiscn in ndrdlichen und mittleren China, Petermanns Mitt., 1901, 47, and 1904, 50. 

t Vol. i, pp. 264 and 277. 

(Report on Upper Paleozoic Fossils, vol. in. 



MARGIN OF THE RED BASIN. 85 

supposed to account for the sharp contact of the red shale on the Wu-shan 
limestone, may be assumed to be of less duration than that represented by 
marked unconformity of dip; and therefore the strata succeeding upon the 
area of marine scour would probably be older than those transgressing upon 
the area of subaerial erosion. The former might be late Paleozoic, as Girty 
suggests. The latter probably range from early Mesozoic to Jurassic. 

The middle Yang-tz'i region, where the strata have been observed by 
Pumpelly, von Richthofen, and ourselves, is continuous on the west with the 
Red Basin of Ssi'-ch'uan. The next notable observations on the Paleozoic- 
Mesozoic rocks relate to the northern margin of that basin near Kuan-yiian- 
hten, in the region reached by von Richthofen, iXiczy, and Obrutchov, and 
already several times referred to. 

South of the section exposed by the Kia-ling-kiang across the folded 
Paleozoics are strata which dip gently southward into the Red Basin. There 
is a marked unconformity, above which the first formation is a massive 
limestone. Von Richthofen regarded it as probably Permian or Triassic.* 
L6czy describes the section observed by von Richthofen in nearly the same 
terms,! and refers the limestone, which has a thickness of 1,400 feet, 400 
meters, or more, likewise to Permian or Triassic. He, however, leaves the 
possibility of a still younger age (Rhaetic) open. In certain thin-bedded, 
light-colored, marly limestones, which are the uppermost strata of the folded 
series beneath the undisturbed supposed Permian limestone, he collected 
indistinct fossils, on which he comments as follows :J 

Among the materials which I collected there occur a cast which resembles Megalo- 
donta, an Aviculopecten, as well as numerous examples of that little bivalve which we com- 
monly designate by the indefinite name of Myacites. These forms permit us to suppose 
that the marly clays and thin-bedded limestones which overlie the supposed Carboniferous 
sandstone may be of Upper Carboniferous age, and that they perhaps are the southern 
representatives of the North China supra-Carboniferous series. But the possibility is not 
excluded that even Permian and Triassic may be included among these disturbed strata, 
and that the evenly bedded limestone which occurs at the base of the middle Jurassic sand- 
stones, in the Basin of Ssi-ch'uan, may belong to the Rhsetic system. I found, in fact, 
the traces of this system in the western margin of the Basin of Ssl-ch'uan, as we shall see 
further on. 

The observation to which I^Sczy refers in the preceding paragraph is 
probably that which he records on pages 736 to 739. In an excursion in 
the vicinity of Tschung-tjen he observed Triassic strata which were appar- 
ently conformably bedded between two heavy limestones, both of which he 
assigns to the Carboniferous. He explains the relations by a conformable 

* China, vol. n, p. 603. Quoted in full in this report, vol. 1, p. 295. 
t Reise des Grafen Szechenyi, vol. 1, pp. 439-440. 
%Ibid. t vol. 1, p. 441. 



86 RESEARCH IN CHINA. 

contact at the base and an overthrust above. The Triassic strata consist of 
sandstones and fine-grained sandy shales, which contain several species of 
Myophoria, as well as impressions of Encrinus liliiformis, together with 
other well-preserved forms. The locality is in western Yun-nan, latitude 
28 , longitude ioo° east. 

The Red Basin of Ssi'-ch'uan was first explored by von Richthofen, but 
his observations still remain unpublished. L6czy crossed the northwestern 
margin only, yet his account affords the best available information.* It is 
quoted in the section on the Jurassic. 

The occurrences which have been described for the Yang-tzi' and Ssi- 
ch'uan are those of strata south of the metamorphic district of the Han 
valley, which borders the southern Ts'in-ling-shan. In the vicinity of Sh'i- 
ts'uan-hidn, along the middle course of the Han, and in that part of south- 
eastern Shen-si which lies between Hing-an-fu and Chdn-p'ing-hten, the 
expedition of 1903-04 observed certain schists, which appear to hold the 
stratigraphic position of the Kui-ch6u series and to have the mineralogical 
character that metamorphic rocks derived from those sediments should 
have. They have been described in volume 1, chapter xiv. 

We observed these metamorphosed Permo-Mesozoic strata about Shl- 
ts'uan-hten in latitude 33 , longitude 108 30' east. The next occurrence 
toward the west which may be assigned to this horizon is described by 
lX>czy,f and presents peculiar characters. It lies north of Kuan-yuan-hi£n 
and is involved in the folds of the Paleozoics near Chau-ti£n. The strata 
overlie the typical Carboniferous limestone and consist of slaty limestones 
and sheared clay slates, which are reddish-brown in color and inclose large 
limestone blocks. I*6czy suggests that they are of Silurian age and are 
overthrust on the Carboniferous, and this may be the case. But it seems 
equally probable that the beds are Permo-Mesozoic and differ from those of 
the same age near Kuan-yiian-hi£n simply in degree of slatiness. If so, the 
relations are similar to those which exist between the altered rocks north 
of Chon-p'ing-hten, Shen-si, and the unaltered beds south of that town. 
The inclusion of large limestone blocks is not explained. They may be 
lenses, peculiar conglomerates, or of autoclastic nature. 

JURASSIC 

Jurassic strata occur extensively in central and southern China, and 
also in northeastern China in the provinces of Shan-tung and Liau-tung. 
The basin of Jurassic coal-bearing strata near Ta-tung-fu in northern Shan- 
si, longitude 113 east, latitude 40°,^ is apparently an isolated occurrence 

* Retse des Grafen Sz6chenyi, vol. i, p. 685. 

\Ibid., vol. I, p. 438. 

t China, vol. n, pp. 35^-359 



OCCURRENCES OF JURASSIC. 87 

far to the northwest, beyond which in Mongolia no deposits of similar age 
occur.* Following the trend of the mountain ranges from Ta-tung-fu 
southwest through Shan-si, we come upon the Jurassic in the eastern Ts'in- 
ling-shant whence it may be traced through various synclines westward 
across Shen-si to the Red Basin of Ssi-ch'uan. The line thus followed 
constitutes the northern limit beyond which neither Wczy nor Obrutchov 
report any observations of Jurassic deposits. 

The formations of this period in China are of the continental type. 
They consist chiefly of sandstones, with shale, generally red, more or less 
associated with coal, devoid of marine fossils, but characterized by plants 
which, north of Indo-China, do not contain Gondwana species, but are 
frequently related to Russian Jurassic forms. 

I proceed to the enumeration of some characteristic occurrences. 

In Shan-tung, in the coal-basin of Wei-hi6n, are strata from which 
Lorenz collected Jurassic plants. % 

In the eastern Ts'in-ling-shan, near Shan-ch6u in Shen-si, L6czy 
observed a basin of Jurassic strata which rest on ancient metamorphic 
schists. He says:§ 

Back of Shan-ch6u the valley is bounded by steep cliffs, in which the steeply up- 
turned transgression of the basin deposits is clearly exposed. As is shown in fig. 30 a, 
the conglomerate beds which, in a gently inclined attitude, underlie Shan-ch6u, assume 
a constantly steeper, almost vertical dip; they are underlain by fine-grained clayey sand- 
stones alternating with dark marly layers, and finally there come in dark, bituminous, 
thin-bedded marls, with thin sandstone layers. These last constitute the lowest strata 
in the basin, and are much folded as a whole in a width of a kilometer. In the marl as 
well as in the sandstones occur numerous carbonized fruits (carpolithus) which Schenck 
described as belonging to cycads or as coniferous fruits resembling taxinea. According to 
him they resemble the fruits of Bairia or Gingko of the Jurassic of Siberia. 

The occurrence thus described by L6czy is peculiar, in that it lies so 
far in the heart of the Ts'in-ling-shan and the strata are more strikingly 
folded than is common with those of like age. 

Some miles south of the above-described occurrence, between "Tse- 
chuen" and "Kiu-tze-kuan," L6czy crossed an extensive basin filled with 
deposits which he in horizontal attitude and consist of the local sediments 
from the surrounding mountains. He speaks of them as Mesozoic, but 
does not cite any evidence, and it would appear not improbable that they 
are of later age. 

♦Loczy: Reise des Grafen Szechenyi, vol. n, p. 799. 

flbtd. t vol. n, p. 415. 

X Beitrage zur Geologie Shantungs, Heft 1. 

§ Reise des Grafen Szechenyi, vol. 1, p. 415, fig. 50 a. 



88 RESEARCH IN CHINA. 

Strata which we provisionally assign to the Jurassic occur at Shl- 
ts'iian-h&n on the Han river, in the form of red and yellow sandstone and 
conglomerate composed of the detritus from older rocks of the vicinity. 
The area is apparently limited and owes its present position and preser- 
vation from erosion to a fault by which the soft young strata are brought 
to a relatively low level among the metamorphosed Paleozoics.* 

Still farther west, in the northern margin of the Red Basin, are the 
Jurassic beds near Kuan-yiian-hi£n, which were first recognized by von 
Richthofenf, again observed by L6czy,J and repeatedly referred to in this 
work. Von Richthofen's section is quoted in volume I, page 295. Above 
the coal-bearing middle Jurassic, as determined by plant remains, come 
coarse conglomerates, 300 feet, 90 meters, thick, followed by yellow, reddish, 
and finally greenish sandstones about 200 feet, 60 meters, thick. The con- 
glomerates appear to mark an invasion of coarse material of local origin, 
which may be ascribed to increasing declivities or to greater precipitation 
in nearby mountains. Together with the overlying sandstone it may with 
reason be referred to the middle or upper Jurassic. 

This occurrence is presumably typical for the Red Basin of Ssi-ch'uan, 
so far as its margins are concerned. Although von Richthofen made more 
extensive observations in this great interior depression of western China 
than any one since, we have no account of them and rely upon L6czy, 
who traversed the northwestern margin. He states :§ 

Immediately upon the early Paleozoic deposits, on the margin of the basin, follow 
the Mesozoic strata. In the vicinity of Ja-ch6u-fu the Carboniferous appears to be wanting, 
as immediately beneath the Ssi-ch'uan sandstone we found Devonian limestone near 
Hoa-ling-pu. Near Kuan-juon, on the other hand, the Carboniferous and Permian strata 
probably occur in the marginal mountains, as has been stated above. 

The Mesozoic systems are represented by the great series of the Ssi-ch'uan sandstones. 
This sandstone formation consists of red and gray sandstones, coarse conglomerates, and 
marly shales, and in its lower layers are huge coal-beds, which are worked at many points 
about the northern and western margins. The coal-beds near Kuan-judn-shien and 
Hoani-pu yielded impressions of plants of the middle Jura (Dogger), whereas near Lin- 
tschi-shien and Ni-tou we collected Liassic plants. 

Marine fossils are not yet known from the Ssi-ch'uan sandstone. The only fragment 
of a mollusk is a doubtful Anoplophora (Cardinia) which was found near Lin-tschi-shien, 
but it is not sufficiently well preserved to afford definite evidence for or against a marine 
origin. 

The Ssi-ch'uan red series is petrographically as well as geologically and structurally 
identical with the red sandstone of the province of Kiang-si, as well as with the basin 
deposits which we saw on the lower Han-kiang and on the Si£-ho. 



* Research in China, vol. i, p. 316 

t China, vol. n, p. 603. 

% Reise des Grafen Szechenyi, vol. 1, p. 440. 

§ Ibid., pp. 685-686. 



STRUCTURE OF ASIA. 89 



PERMO-MESOZOIC DIASTROPHISM. 



The diastrophic movements which occurred in all continents during 
the closing epochs of the Paleozoic and the initial epochs of the Mesozoic 
were pronounced and prolonged throughout Asia. They ultimately changed 
that face of the globe, as Suess has pointed out,* welding together the sepa- 
rate elements of the Asiatic continent, except that the Angara and Gond- 
wana lands remained separated by the Himalayan strait. In contrast to 
the gradual changes of level which had characterized the Paleozoic, these 
disturbances were of decidedly orogenic character. They gave rise to 
mountain systems, which are structurally still the controlling features of 
Asia. The foundations of the ranges are now raised to the summits of 
the Ti&i-shan, Kuen-lung, and Ts'in-ling-shan, and the substance of their 
masses constitutes the Triassic and Jurassic sediment of Asia. By Cre- 
taceous time the continent was again low. 

The continental structure of Asia has been so elaborately described 
by Suess, f the master of the subject, that extended discussion is superfluous 
unless based on new data; and in general such data are not yet available. 
Furthermore, what later information we have confirmed his deductions, as 
regards the trends of mountain axes. We may, however, point out that 
the Sinian is more generally folded in North China than von Richthofen, 
and consequently Suess, supposed. And our observations give additional 
data on the structure of the Wu-t'ai-shan, the Ts'in-ling-shan, the Han 
district, and the middle Yang-tzi region. 

On the map, plate 8, are shown the structural lines given by Suess, X 
supplemented by those traced by Futterer§ south of latitude 36 . 

Referring to these authors for their presentation, I proceed to discuss 
some of the newer significant facts. 

Through his reconnaissance observations in Shantung von Richthofen 
gained the impression that Sinian strata had not been folded, and in pass- 
ing through the Wu-t'ai district he was so circumstanced that he did not 
observe the actual facts of structure. Our observations in the Ch'ang-hia 
district of western Shantung showed that the Sinian is folded and even 
overthrust, the axial trends being dominantly northeast-southwest and 
subordinately northwest-southeast. || And in the Wu-t'ai district the 
Sinian and Carboniferous exhibit overfolds and overthrusts of a decided 



* La Face de la Terre, vol. in, p. 24. 

f/fci., vol. in. 

X Ibid., vol. ni, pi. m. 

S Pctcrmanns Mitt. Erg., Heft 119. 

B Vol. 1, chapter ni, and plates xm and xv. 



90 RESEARCH IN CHINA. 

character, which there extend northeast to southwest, parallel to the 
structure of the pre-Sinian sediments.* 

To what extent these structures are general in North China is not yet 
determinable. The Ch'ang-hia district is a very limited area; the folding 
is moderate and probably local. The folds of the Wu-t'ai district are much 
more pronounced and occur in a zone of ancient deformation which is mar- 
ginal to the masses of Mongolia and Ordos. It is traced from northern 
Chi-li across Shan-si to Shen-si, a distance of 500 miles, 800 kilometers, and 
is a structural zone of the first order, which is represented in modern moun- 
tain systems by notable heights. Southeast of it lies the plateau of eastern 
Shan-si, which, in the southern part where von Richthofen crossed, presents 
the Paleozoic in little disturbed strata. It is possible, but not known, that 
no folds invade its broad area. 

The date of deformation in North China is fixed as not earlier than 
upper Carboniferous (Pennsylvanian) by the parallelism of strata of that 
age with the Sinian over wide areas, and as pre-Liassic by the unconformity 
which was observed by von Richthofen between the Sinian and the Liassic 
coal-measures of the Ta-tung-fu field in northwest Shan-si. The latter 
strata are also tilted, probably in consequence of a recurrent movement in 
Jurassic time. 

As was first pointed out by von Richthofen, the Ts'in-ling-shan, 
the eastern continuation of the Kuen-lung system, occupies the site of a 
trough in which Paleozoic sediments accumulated to considerable thickness, 
if the consensus of opinion regarding the age of the metamorphosed sedi- 
ments be correct. Its folds embrace the southern margin of the ancient 
land mass that is now northern Shen-si and Kan-su. The trend of the axes 
of folding in that part of the range east of longitude 108 is not exactly 
parallel with the modern height. Von Richthofen 's preliminary map, a 
bold essay on the slight data available to him, was mistaken in this respect. 
The range trends about north 75 east, and the general axial strike of the 
structures varies from east-west to north 8o° west. Thus the belts of the 
Archean, Proterozoic, and Paleozoic strata in general approach the northern 
front at an angle and are cut off by the fault, which is the latest tectonic 
feature. The angle is an acute one, and in the case of the contact of the 
Proterozoic and Paleozoic south of Ch6u-chi-hi6n, the line trends south of 
west; but the larger features of the structure diverge from the range and 
pass under the Wei valley, where they are faulted down. 

The Ts'in-ling-shan and the mountainous region south of it, through 
which the Han flows from Han-chung-fu to beyond Hing-an-fu, was the 
scene of more or less intense metamorphism and intrusion, as well as of 

•Vol. i, chap. v. 



PKRMO-MESOZOIC INTRUSIONS. 9 1 

folding. In the section observed by L6czy, in longitude 106 east, in that 
previously observed by von Richthofen in longitude 107 30' east, and in 
that of the expedition of 1903-04 in longitude 108 15' east, there are areas 
of slates, argillites, schists, and gneisses, apparently derived from Paleozoic 
sediments and associated with large masses of intrusive diorite or granite. 
In the last-named section two large granite masses and several smaller ones 
present a total width of 19 miles in 84 miles. They are intrusive bands, 
whose length along their trend parallel to the axis of the range is very 
considerable. Their effect in altering adjacent strata is extremely variable, 
the limestone of the Hei-shui series near I,iu-yu6-ho (atlas sheet a 2) being 
but little affected a hundred feet from the contact, whereas near Ssi-m6u-ti 
(atlas sheet a 3) the Paleozoic strata are generally and intensely metamor- 
phosed, although the intrusions as they appear at the surface are much 
smaller. 

The date of these intrusions is later than the folding, as the holocrys- 
talline intrusive rocks were not sheared, but it is presumably not much 
later. Among the intruded and metamorphosed strata we believe we have 
identified the K'ui-ch6u formation, i. e., Permo-Triassic, which may have 
been contemporaneous with the early effects of deformation, but which was 
involved in the later effects to the extent of overfolding and overthrusting. 
And unconformably above the metamorphosed strata occur the unaltered 
Shi-ts'uan sandstones, which we correlate tentatively with the middle or 
upper Jurassic sandstone of the Red Basin of Ssi'-ch'uan. These data seem 
to confine the episode of intrusion to the Triassic or early Jurassic, to the 
close of the period of diastrophism. The inference is strengthened by the 
fact that there are not any Cretaceous or early Tertiary sediments of marine 
or continental character, such as should occur as a result of erosion if, 
during those periods, there had been great intrusions of granite, with the 
probable accompaniment of decided elevation. 

The region within which the early Mesozoic intrusions occur is not yet 
well defined. In the western Ts'in-ling-shan, between longitudes 107 and 
108 east, the zone may be said to extend from the Wei" to the Han valleys, 
between latitudes 33 and 34 10' north. In longitude 109 30' its southern 
margin is near ChSn-plng-hten, latitude 31 50'. The eastern and north- 
eastern extension is indefinite, as the great granite masses of the eastern 
Ts'in-ling-shan, which may in part belong to this period, are described 
by L6czy and von Richthofen as "Archean." Toward the northwest, in 
longitude 105 east, latitude 35 , near "Kun-tschang-fu" L6czy * observed 
intrusions of granite in mica, amphibole, and chlorite schists. The occur- 
rence is one of many granite masses which characterize the northwestern 

*Rdse des Grafen Sz&henyi, vol. 1, p. 425. 



92 RESEARCH IN CHINA. 

Ts'in-ling-shan, and appear to be part of the zone under consideration. 
The western continuation of the mountain system, the Nan-shan ranges, 
was a scene of igneous intrusions, as described by Obrutchov, but whether 
of pre-Cambrian, middle Paleozoic, or Mesozoic date we can not distin- 
guish. In western Ssi-ch'uan, longitude 99 to 103 east, latitude 30* north, 
between Ba-tang and Ja-ch6u (Ya-ch6u), where Paleozoic and Mesozoic 
strata are folded around the eastern margin of the Tibetan plateau, L6czy 
observed great bodies of granite in the metamorphic schists. He com- 
pares the rocks with the Nan-shan sandstone, and again we are uncertain 
whether the intrusions are pre-Cambrian or Mesozoic. In this connection 
it is worth while to point out that the Ts'in-ling-shan and the Alps of west- 
ern Tibet bound the depressed basin of Ssi-ch'uan on the north and west 
and coalesce at its northwestern corner. The geologic conditions which led 
up to the Permo-Mesozoic diastrophism were identical in the two belts, so 
far as the stratigraphic history is concerned; the effects of folding appear 
to have been much the same; and it is probable that the phenomena of 
intrusion which affected the one occurred in the other. The southern con- 
tinuation of the mountains of Ssi-ch'uan and Yunnan extends through 
Indo-China, where Fuchs and Saladin distinguish an ancient granite and a 
microgranulite of Carboniferous or post-Carboniferous age.* In view of 
the reconnaissance nature of the observations the age of the ancient granite 
may be considered undetermined and possibly Mesozoic. 

In this connection it is desirable to mention the fact brought out by 
Haydenf in course of the Younghusband expedition to Tibet that Jurassic 
and Cretaceous strata of southeastern Tibet, south of Lhasa, are highly 
metamorphosed and intruded by granite. At first thought the suggestion 
occurs that the post-Cretaceous age of these intrusions may indicate a like 
recency for the intrusions of the Ts'in-ling-shan; but the unaltered char- 
acter of the supposed Jurassic in that region appears to preclude the idea ; 
and it is more likely that the events in the Ts'in-ling-shan and in south- 
eastern Tibet are successive than that they were contemporaneous. 

In strong contrast to the pronounced folding, metamorphism, and 
intrusion that characterize the central Ts'in-ling-shan and the Han valley 
is the moderate deformation of the region on the south. Folded Paleozoic 
strata, which are indeed closely folded and even overthrust, but not altered, 
adjoin the metamorphic district along a remarkably sharp boundary, and 
pass into the wide flexures of the middle Yang-tzi or the synclinorium of 
the Red Basin. On the Yang-tzi there is complete conformity of dip up to 
and including the K'ui-ch6u beds (Rhaetic). About the Red Basin there 



* Annates des Mines, 1882, 8me serie, Memoires 2, pp. 224-225. 
f Report Oeol. Sur. of India, 1905. 



DURATION Ot FOLDING. 93 

are unconformities. That near Kuan- yuan -hi^n is overlain by limestone 
which may be Permian or Rhaetic, as already stated. But west of Ja-ch6u* 
the Mesozoic sediments are conformable to the underlying Devonian and 
are folded with it. Hence L6czy infers that the folding continued longer in 
the latter region. It is possible that the vicinity of Ja-ch6u was outside the 
zone of Permo-Mesozoic folding, as most of the Red Basin was, and became 
involved in disturbance only when the Himalayas were compressed in the 
great post-Eocene epoch of diastrophism. In the zone of the great mountain 
chains of northern India, the Permo-Mesozoic movement was manifested 
only in variations of sediment, not in folding. 

♦Rcisc des Grafen Sz6chenyi, Loczy, vol. i, p. 690. 



CHAPTER VIL— CONTINENTAL ASIA, 



CRETACEOUS. 

A geologist taught only by observation in China, outside of Tibet, 
would know nothing of the Cretaceous. No strata are known which may be 
correlated with the strata that represent the period in America and Europe. 
We would look for marine or continental deposits in the middle Yang-tzi 
region or the Red Basin of Ssi'-ch'uan, where they might cap the Jurassic 
in the deeper synclines ; or about the margins of the great alluvial plain of 
the Yang-tzi" and the Huang -ho, where they might outcrop in the foothills; 
but they are not found. If they ever existed above the known Jurassic they 
have been eroded ; if they underlie the plain they are overlapped. 

Nor are Cretaceous strata of any kind known in the vast area of Asia 
north of Tibet, east of the Urals, and south of northern Siberia. No other fact 
than this, perhaps, more sharply challenges the hypothesis that the present 
mountain ranges and basins of central Asia date from a pre-Cretaceous 
time. Highlands without waste and waste without deposit in these interior 
basins are inconceivable; but though the plateaus are affected by post- 
Cretaceous dislocations which expose even the ancient crystallines, there 
is no trace of deposition during the Cretaceous period. The surface that 
could for so long a time maintain a blank record must have been a land 
in which transportation and aggradation had ceased in consequence of 
uniformity and flatness of slope — a well-developed peneplain. Even on 
such a surface subaerial decay must produce residual material and the 
atmosphere do some work; but the product might be worked over into 
later deposits, as it probably has been. 

Some of the waste from this Cretaceous land found its way into the 
southern Tethys, where it formed the Giumal sandstone. The area of 
deposition extends throughout the Himalayas, over southern Tibet, and 
through Kashmir into Afghanistan and Persia.* 

The rock is a greenish-gray sandstone, sometimes very siliceous, and 
of considerable thickness. There is a transition to it from the underlying 
Jurassic shales, and it is separated by a sharp but conformable contact from 
the overlying upper Cretaceous limestone, which extensively overlaps it. 
Thus, in the latest Jurassic, lower Cretaceous, and upper Cretaceous of 

♦Griesbach: Memoirs G. S. I. xxm, p. 81. 

95 



96 RESEARCH IN CHINA. 

northern India we have the sedimentary record of the reduction, peneplana- 
tion, and partial submergence of the continent, which in preceding Mesozoic 
time had attained very prominent relief. 

TERTIARY AND QUATERNARY. 

A sedimentary record of the Tertiary history of China is wanting, as 
is that of the Cretaceous. We turn to Indo-China, India, southern Tibet, 
and western Asia, for occurrences of marine and estuarine deposits, which 
by their calcareous or carbonaceous character show that the peneplain 
conditions of the Cretaceous period were continued, at least in southern 
Asia, through the Eocene and Oligocene and well into the Miocene. The 
marine zone which was the southern branch of the Tethys persisted along 
the Himalayan region and still divided the ancient Gondwana land of the 
Indian peninsula from Tibet. The movements which, during the Oligocene 
and Miocene, closed the strait, are described by Griesbach,* who, in a lim- 
ited exploration of the Hundes plateau of southern Tibet, distinguished 
altered nummulitic limestone, unconformably overlain by Miocene (?) sand- 
stone, a few hundred feet thick, which in turn is conformably covered by 
a great thickness of nearly horizontal beds that Lydekker determined on 
the evidence of mammalian bones to be probably Pleistocene and certainly 
not older than Pliocene. The recent observations by Hayden in the prov- 
ince of Tsang and U along Younghusband's route to Lhasa have confirmed 
Griesbach *s observations, f 

The evidence of stratigraphy north of the range agrees with that of 
the Siwaliks of the southern foothills, and there is every reason to accept 
Oldham's view that much of the elevation of the Himalayas has occurred 
since the Miocene epoch. t In view of the evidence that other mountain 
systems of Asia have grown to great heights during the Pleistocene it may 
be questioned whether the Himalayas reached their present altitude during 
the initial movements of folding; it is even probable that they have suffered 
one partial epoch of erosion to advanced maturity and have since been 
warped up, as have the Apennines and Karpathians;§ but they in any 
case represent the latest effects of the compressive force which has welded 
Asia into a continent. 

History repeats itself, now here, now there. The northern Tethys 
was closed by a late Carboniferous movement, during which the Kuen-lung 
system of folds developed; and the supra-Carboniferous sandstones were 

* Central Himalayas, Memoirs G. S. I. xxiii, pp. 82-87. 

fGeology of Tibet, Rec G S. I., 1905. 

t Manual of Geology of India, second edition, 1893, p. 479. 

§ Studies in Europe, B. Willis, Year Book of the Carnegie Institution of Washington No. 4. 



CONTINENTAL DEPOSITS. 97 

spread upon the flanks. The strata that form the Ts'in-ling-shan and the 
Alps of western Tibet shared in the Kuen-lung movement, but they also 
suffered a later intense disturbance, which gave rise to the erosion cycle 
that is represented in the Jurassic sandstones. And the Himalayan zone, 
which, until post-Eocene time had not been folded, then became the locus 
of pronounced deformation and passed through the movements that are 
evidenced by the unconformities and sediments of the Tertiaries. L6czy 
noted that the Jurassic beds of Ssi'-ch'uan and the supra-Carboniferous of 
central Asia* are similar products of vigorous erosion of mountain ranges 
that were elevated at separate times; and we may add the Hundes and 
Siwalik sandstones as a third group of formations of the same kind. 

With the epoch of mid-Tertiary folding the compression of Asia ceased 
for a time at least. The flat Hundes sandstone has its equivalents in the 
essentially flat Pliocene and Pleistocene deposits of central Asia and Siberia. 
The record is one of erosion and wide-spread deposition in basins, either 
lacustrine or arid, and on fluviatile plains. But diastrophic movements 
have not ceased ; they have taken on the form of normal faulting, involved 
in spreading of the continent, and the major features are accented by the 
fractures. These phenomena, which are extreme effects of vertical warp- 
ing, are chiefly of Pleistocene age. 

I proceed to consider the evidence of orogenic movements other than 
folding; it is subordinately stratigraphic and predominantly physiographic. 

Before considering the Quaternary warping it is well to describe in 
proper sequence the Tertiary dislocations of the same type. In north- 
eastern China, in the provinces of Shan-tung and Chi'-li, are two districts in 
which normal faulting is the principal structural fact. They have been 
mapped and described in volume I, so far as we saw them ; and we have 
there cited observations by von Richthofen, who noted the faults of Shan- 
tung as the principal structural facts of that province. The district in 
Chi-li is that which we call the Ning-shan basin, west of Pau-ting-fu, and 
has not been seen by any other geologists. 

The evidence of faulting in these cases is chiefly stratigraphic: Paleo- 
zoic faulted down in contact with Archean, along throws which range up to 
10,000 feet, 3,000 meters, or more; but in Shan-tung the relief due to dis- 
placement still survives, though it is greatly dissected. Fault-scarps have 
receded one or two miles ; fault-blocks are cut into isolated sections by the 
valleys of consequent streams that originated on the scarps; valleys have 
widened and mountain masses have become skeletonized. The volume of 
rock removed is very large, but since the districts have had open drainage 
to areas now submerged or buried beneath recent alluvium, there are no 

* Rdae des Grafen Sz&henyi, vol. 1, p. 799. 



$& RESEARCH IN CHINA. 

accessible deposits corresponding to the cycle of erosion. We are thus 
restricted to physiographic evidence in seeking to date the epoch of faulting, 
but, by comparing the effects of erosion with those accomplished elsewhere 
since the middle Tertiary, we reach a probable conclusion that the time was 
pre-Miocene. 

In the Ning-shan district of Chi-li the relief due to faulting no longer 
survives; indeed it has been reversed, limestone hills on the downthrow 
rising 1,000 feet, 300 meters, above the surface of gneiss on the upthrow. 
Hence we infer that the faulting may be somewhat older than that in Shan- 
tung, and we place it in the earliest Tertiary. 

The faulted district of western Shantung and that of Ning-shan in 
Chi-li are isolated occurrences in eastern Asia, so far as we now know, of 
dislocations of early Tertiary age. Yet it is probable that they are not 
singular, and anticipating somewhat the discussion of physiographic cycles 
which follows, it is desirable to state in this connection the conclusion 
reached by Suess, that the profound graben which is occupied by Lake Bai- 
kal has existed since the close of the Tertiary period.* The evidence, which 
consists of the survival of species of European Pliocene affinities in the lake, 
is clearly assembled, and the age of the basin appears well established. The 
depression is due to normal faults, which define the graben and which are 
paralleled by others that give rise to the ranges of Trans-Baikalia. Attrib- 
uting to the system the age determined for the lake basin, we recognize 
in Trans-Baikalia a mountain group of late Tertiary date. 

It will be seen by reference to volume 1, that the faults which charac- 
terize the Ki-ch6u-shan, Ho-shan, Hua-shan, and Ts'in-ling-shan, all of 
which are mountain ranges in Shan-si and Shen-si, China, are referred to a 
Quaternary, probably middle and late Quaternary, date. Hence, taking 
account of the Chi-li, Shan-tung, Baikal, and Shan-si fault-systems, I con- 
clude that normal faulting has been a feature of orogenic activity in Asia, 
in one district or another, since early Tertiary time. 

Warping, that is, nearly vertical displacement of different parts of the 
surface to unequal amounts and often in opposite directions without dislo- 
cation, has been a general effect of dias trophism, especially during the later 
Tertiary and Quaternary. And the displacements have been so conditioned 
in time and place as to give rise to cycles of erosion, which can be distin- 
guished in the plains, plateaus, ranges, and rivers of the continent. They 
have been described in the physiographic study of the districts through 
which we passed, as presented in volume 1. There the surface is analyzed, 
the development of streams is traced, and the interaction of diastrophic 

♦La Face de U Terre, vol. in, p. 78. 



PHYSIOGRAPHIC STAGES. 99 

movements with erosion is presented. The climatic factor is also recog- 
nized and applied to aid in fixing the date of initial loess deposition. 

Pour phases are distinguished : the first or oldest is a peneplain, a very 
ancient and also very aged form, which is known from various parts of 
northern Asia, and a remnant of which we named from its preservation in 
the highest dome of the Wu-t'ai-shan, the Pei'-t'ai form, developed during 
the Pei-t'ai cycle. 

The next younger is a surface of mature erosion, which replaced any 
older features in most of the areas we saw. It is a surface of moderate 
relief, characterized by wide valleys and hills rarely a thousand feet high. 
It is typically developed near T'ang-hten, Chx-li, and we call it the T'ang- 
hi£n stage. 

The third phase was one of aggradation in North China, the time of the 
early loess deposits. The moderate relief of the preceding stage was to a 
notable extent buried beneath the Huang-t'u, a formation consisting of 
wind-sorted waste from the deserts of central Asia, whence the dust was 
brought chiefly by rivers. The partly buried hills along the western mar- 
gin of the Great Plain of eastern China afford an illustration of the aspect 
of Chi'-li, Shan-si, and northern Shen-si at the time. The great mountain 
ranges had not attained their present height. Attributing the desert waste 
to the climatic change from Tertiary to Pleistocene, which may have 
become effective in late Pliocene to the extent observed, we assign this 
phase to that time and to the opening of the Pleistocene. We designate it 
the Hin-ch6u stage, after the Hin-ch6u loess basin in Shan-si. 

The fourth and present physiographic stage we named for North China 
the Fon-ho, from the river of that name, which, though older than the Fon- 
ho epoch, still flows through Shan-si among characteristic features of that 
stage. For South China, where the physiographic relations are somewhat 
different, we applied the name Yang-tzi' to what is very nearly or precisely 
the same time division. It is an epoch of very decided mountain growth in 
China ; and if, as I believe, the principal continental upwarp of central Asia 
is largely of the same date, it is the time of one of the most remarkable 
diastrophic movements of which we have knowledge. It appears to fall 
chiefly within the Quaternary, but may extend back into the Pliocene. 
The typical features are warped and faulted surfaces, which result from 
downward and upward movements of adjacent masses that underlie basins 
and graben or constitute plateaus and mountain ranges. The amount of 
sculpture is relatively slight, but great canyons like the Yang-tzi gorges have 
been cut by antecedent rivers. 

Having thus summarized the results of our observations in China, I 
suggest their broader relations. 



IOO RESEARCH IN CHINA. 

The oldest, the Pei-t'ai cycle, links the physiographic history with the 
stratigraphic record. We have seen that in the sediments there is reason to 
regard the Cretaceous as a time when Asia presented the aspect of an exten- 
sive peneplain, over which the sea transgressed from the south. Sediments 
of the Eocene and Oligocene epochs record the same conditions. We regard 
the Pei-t'ai as the equivalent surface, and the Pei-t'ai cycle as covering late 
Cretaceous and early Tertiary. It is the Asiatic representative of the 
Schooley or Kittatinny peneplain of the eastern United States and of the 
Cretaceous peneplain of central Europe. 

The remnant of a peneplain which we recognized in Pei-t'ai by its form 
and by the residual soil peculiar to it, is of very small extent, and we may 
well ask what other evidences remain to support the inferences of a once 
general condition. Let us proceed northeastward from the Wu-t'ai-shan, 
which is in northern Shan-si, and review some known features, bearing in 
mind that the ancient surface is both warped and eroded; consequently 
it may occur at any altitude and may be more or less dissected. Where 
the Siberian railroad, after leaving the dislocated mountainous region of 
Trans-Baikalia, traverses northeastern Mongolia to the Khingan range and 
descends into the valleys of Manchuria, there is a plateau surface which 
is a slightly warped plain of erosion, occasionally capped by lava flows. In 
the Khingan range it is warped a few hundred feet higher and, extending 
over the crest, is represented in the summits of the long spurs which consti- 
tute the deeply canyoned eastern slope. In Manchuria it sinks beneath 
the alluvium of the Sungari, as the tilted peneplain that forms the western 
slope of the Sierra Nevada of California sinks beneath the alluvium of the 
Sacramento. 

Suess refers to the eastern slope of the great Khingan range in its north- 
ern extension as being analogous to a flexure, and gives the following account 
of the great plain of the Amur :* 

The constitution of the plain which extends northward from the upper Amur is not 
altogether simple. Even at the eastern base of the Khingan, beds of the Angara series 
appear * * * and occupy all the west of the plain ♦ ♦ ♦. They are covered 
by white sands and shales with lignite of Tertiary age, which occupy the eastern portion 
of the plain as far as the Ztia river * * *. But this mantle of Tertiary has in general 
only a slight thickness; beneath it appear, as upon the upper Tygda, the Archean rocks 
which play scarcely any orographic role. * * *. In the occasional outcrops of the 
Archean basement M. Ivanov recognized the general strike of north-northeast, but accord- 
ing to this observer the Angara strata which form the western part of the plain are not 
horizontal; on the contrary, along the Amur, in the strip between the great Khingan and 
the first outcrops of the Archean basement, they appear folded with the same north-north- 
east strike. The plain owes its origin to the degradation of these folds. 



♦La Pace dc U Tcrre, vol. m, p. 155. 



. • 






PBI-T'AI PLAIN IN SIBERIA. * ; K)I 

• • 

This description gives definite information regarding the occurrence . 
of a peneplain which is clearly older than the Tertiary deposits which cover* ■:'.•' 
it, and may fairly be correlated with the Pei-t'ai plain. 

With reference to the mountains which lie north of the Amur between 
longitude 120 and 140 east, and which are known as the Aldan or Stanovoi 
range, Suess quotes Krapotkin as saying, "That the supposed continuous 
chain of the Stanovoi range, serving to divide the waters of the Arctic ocean 
from those of the Pacific, does not exist, whether one thinks of it as high 
or low, abrupt or flattened."* 

And again, referring to the Vitim plateau, which is north of the ranges 
of Trans-Baikalia, between 1 io° and 120 , he quotes Krapotkin to the effect 
that over a great distance the country has lost all individuality. 

The travelers who have there sought to follow the line dividing the two slopes have 
not discovered a long and continuous mountain chain, but have found, on the contrary, 
virgin forest, rocks covered with moss, and vast swamps interrupted here and there by 
lakes. 

The region thus described is connected by a long slope with the plain 
of the Amur, and descends on the northwest to the great plateau of horizon- 
tal Paleozoic rocks in which the Lena has sunk its modern canyon. There 
can be little doubt that the vast expanse of plateau and plain in northern 
Siberia, from the range of the Verkojansk mountains on the east to the 
recent alluvium of the Ob on the west, is a great peneplain like that of the 
Canadian highlands of North America; and traced as it is by the unbiased 
observations of Krapotkin, Ivanov, and other observers, to a position 
beneath the Tertiaries of the Amur basin, it may well be assigned to an 
early Tertiary and Cretaceous epoch. 

I have seen the representative of this peneplain in the vicinity of Kras- 
noyarsk, where it forms the summit of the hills that bound the valley of the 
Jenissei', and observed it in the foothills of the northern Altai as far as 
Irkutsk. From the railroad train one can see the long line of the old topo- 
graphic surface rising higher and higher in the mountains toward the south, 
and an observer familiar with the features and interpretation of the Appa- 
lachian mountains can not doubt that he has here in northern Asia a warped 
peneplain, which, like the Schooley peneplain, is somewhat extensively 
dissected. 

The preceding observations may all of them be said to be marginal to 
the great highlands of central Asia, and although the Pei-t'ai surface lies 
at an altitude of 10,000 feet, 3,000 meters, it may be considered a daring 
proposition to extend an inference regarding the peneplain to the highest 

♦La Face de la Terre, vol. in, p. 145 












- •. 



• • • • 

• • • • 



• • i 

• • • 






\OZ . RESEARCH IN CHINA. 

• •• * "• 

• * 

; . /plateaus of the world. But we need not rest upon mere inference. Davis 
. r has described the summit character of the various ranges of the Ti&i-shan.* 
He says: 

Certain observations made in the central and northern ranges [of the Ti£n-shan] near 
lakes Son-kul and Issak-kul, and on the steppes that border the mountains on the north, 
led to the belief that the region had been very generally worn down to moderate or small 
relief since the time of greater deformation, which probably occurred in the Mesozoic age; 
that large areas of subdued or extinguished mountain structures are still to be seen in 
the low ranges and in the steppes north of the Hi river, and that the present relief of 
many of the higher Ti£n-shan ranges is the result of a somewhat disorderly uplift and of a 
more or less complete dissection of dislocated parts of the worn-down region. Mr. Hunt- 
ington's report shows the application of these conclusions to a large part of the central and 
southern T&n-shan. 

We have no direct evidence of the age of this peneplain, which is now 
elevated to altitudes approaching 14,000 feet, 4,200 meters, but the perfec- 
tion of the profile of the Bural-bas-tau and other ranges sketched by Davis 
suggest that they have not long been exposed in their present altitude. 
And when we consult the geologic section of the adjacent region of western 
Turkestan, we find no record earlier than the middle Tertiary of volumi- 
nous deposition, such as the mountains are capable of yielding. 

The descriptions of Mongolia and northern Tibet give the physiog- 
rapher no reason to expect that an ancient topographic surface may there 
survive. Much of the region is buried beneath Pliocene and Quaternary 
sediments, and the deeply sunken surface of the hard rocks is hidden from 
view. The mountain ranges which rise above the sands have been sharply 
sculptured and appear to be the skeletonized edges of warped and tilted 
blocks. While it is possible that Davis's observations of the Ti^n-shan 
may be repeated elsewhere in the Kuen-lung or the Nan-shan, it is more 
probable that our own experience in the southeastern extension of these 
ranges, the Ts'in-ling-shan, will be paralleled, and that the observer will be 
able to recognize nothing older than a mature surface of late Tertiary date. 

When we consider that physiographic studies have been applied to the 
interpretation of the features of Asia only within the last three years, it 
arouses some surprise to find so much evidence of a surviving peneplain; 
but that evidence appears to deserve frank recognition in view of the series 
of events leading up to the early Tertiary, the stratigraphic record of the 
Cretaceous and Tertiary, and the character of plateaus and plains of denu- 
dation which so much of the land presents, even at high altitudes. 

It is, however, improbable that an entire continent of such extent as 
Asia should be completely peneplained. In America the peneplanation 
of the Cretaceous period failed to reduce the Unaka mountains of North 

* Explorations in Turkestan, Carnegie Institution of Washington Publication No. 26, p. 72. 



PHYSIOGRAPHY AND W>BSS. 103 

Carolina* and the erase being considered generic it was proposed that an 
extended group of heights surviving above a peneplain should be called a 
"unaka." It is highly probable that one or more unakas will be found in 
Asia. 

The dissection of the Pei-t'ai peneplain (using that name tentatively 
as a general term) has proceeded differently in different regions. Where the 
plain is buried beneath Tertiary deposits, as on the Amur, it may be said 
to be intact. Where it has been slightly warped or elevated to a moderate 
height over vast areas, as in northern Siberia, it is still clearly recogniz- 
able in the featureless plateaus. It may also be seen as a general line of 
some mountain profiles where its surface is more steeply tilted, as in the 
northern Altai. It is found as a mere remnant in such summits as the 
Bural-bas-tau and Pei-t'ai. It is no longer to be seen in districts such as 
Shan-tung, where early Tertiary faulting gave rise to acutely accented 
relief; nor in the Ts'in-ling-shan, where warping in mid-Tertiary time 
occasioned the development of a mature but hilly landscape. 

Throughout North China we can distinguish three phases of physio- 
graphic development later than the Pei-t'ai plain : the T'ang-hten, one of 
mature erosion ; the Hin-ch6u, one of aggradation ; and the Fon-ho, one of 
mountain growth. In central China we recognized but two : the Ts'in-ling, 
which corresponds to the first two; and the Yang-tzi, which is probably 
closely equivalent to the Fon-ho. 

The distinction between the T'ang-hi£n and the Hin-ch6u epochs 
depends upon the accumulation of the early deposits of loess, which covered 
a vast area, but an area conditioned by depression and geographic position 
with reference to streams flowing from the basins of central Asia. These 
conditions were by no means universal ; they were bounded on the south by 
the hill district of the Ts'in-ling-shan; and it is probable that outside the 
region of their extent the distinction between the epochs can not be made. 
The equivalent phase of mature topography, which we have called the Ts'in- 
ling phase, will then be found where any feature older than the Fon-ho or 
Yang-tzi' stage is recognizable. 

The Ts'in-ling stage of topographic development characterizes the sum- 
mit views of the Ts'in-ling-shan, the mountains of the Han valley, and the 
ranges of the middle Yang-tzi* region, where we traversed them from the 
Wei valley to I-chang on the Yang-tzi. It is marked by more or less decided 
mature relief, above well-developed valley floors, in which the younger 
canyons are cut. It presumably succeeds the Pei-t'ai peneplain, though the 
earlier existence of the latter in this region can not be demonstrated, since 
erosion progressed too far in the Ts'in-ling cycle. /* certainly replaces the 
tectonic relief which resulted from the Permo-Mesozoic folding. 

*Qeomorphology of the Appalachians, Hayes and Campbell, Nat. Geog. Soc. Mag., vol. vi, p. 63, 1894. 



IQ4 RESEARCH IN CHINA. 

The last statement runs contrary to the views of many geologists, and 
particularly to the views of those who hold with the master, Suess, that the 
present mountain ranges are a direct consequence of the compressing forces 
that folded the strata within them. There are, indeed, two distinct points 
of view, each of which is the outcome of observation in a region that by its 
special character determines the inference. With a few exceptions, Euro- 
pean geologists are dominated by the stupendous structures of the Alps, and 
have neglected physiographic studies. American observers twenty years 
ago discovered a new line of interpretation in physiography, and applying 
it first to the Appalachians have since extended it to other ranges and con- 
tinents. In the light of present knowledge it appears safe to generalize as 
follows : Those mountain chains which exhibit folded structures of post-Eocene 
development owe their elevation in part possibly to the original effects of that 
compression, and in part to subsequent efforts of a force acting in the same 
sense, but producing upwarps and downwarps that are independent of anti- 
clines and synclines, yet related in general position and trend to the folded 
chain as a whole. On the other hand, altitudes due to folded structures of the 
PermO'Mesozoic or older epochs of diastrophism were long since planed away 
by erosion, and though the structures may be involved in relatively modern 
upwarps, they are not related to the existing elevation. This is true in 
spite of the general fact, inherent in the broader continental and oceanic 
features of the earth, that some zones of orogenic activity retain their 
dynamic character from an early geologic date to the present, as witness 
the Wu-t'ai-shan. 

There are thus two types. Of the former, characterized by post- 
Eocene folding and later warping in the same sense, the Karpathians 
are the best known example,* the structure and physiography of the Alps 
being too obscure to serve as a type. The second, characterized by Permo- 
Mesozoic folding, peneplanation, and relatively recent warping, is repre- 
sented by the classic Appalachians. 

In a region where the relief is directly due to anticlinal elevations and 
synclinal depressions the relation between the altitudes and the structures 
must be such that the anticlinoria at least correspond to heights and the 
synclinoria to lows. A case in point is that of the Lewis range in Montana,f 
where the altitudes bear these relations. But these relations do not hold 
for the mountains of Central China; their heights and lows are related to 
upwarps and downwarps, which are not coincident with the complex and 
intruded structures of Permo-Mesozoic time, but are everywhere sculptured 

* European Studies, B. Willis, Carnegie Institution of Washington Year Book No. 4. Bau und Bild 
der Karpaten, by V. Uhlig, in Bau und Bild Oesterreichs, Wien, 1903. 

t Stratigraphy and Structure of the Lewis and Livingston Ranges, B. Willis, Bull. G. S. A., vol. xui, 
P. 346. 




WARPING AND FAULTING. 105 

with the mature erosion forms of the Ts'in-ling stage. And strictly accord- 
ing to the later warping and faulting are the depths of the young canyons, 
which pursue courses that are in some measure consequent on the slopes of 
recent upwarps, but in general inconsequent to the older structure. The 
present relations of altitudes and folds show that tectonic elevations of 
Permo-Mesozoic age have given place to warped elevations of modern age ; 
and the physiographic record makes it clear that one or more periods of 
little or no elevation intervened. 

The present topographic cycle, which we may call either the Fon-ho or 
the Yang-tzi cycle, is characterized by the development of basins, warped 
surfaces, fault-scarps, and great mountain ranges, and consequently also by 
youthful erosion forms and extensive plains of aggradation. The scarp, 
the canyon, and the alluvial fan are the marked accents of the cycle and 
are the noted features of Asiatic topography. The warped surface that 
bears the sculpture of a preceding cycle is also of general occurrence, but 
has less often been noted. 

The map, plate 8, comprising the Chinese Empire and parts of adja- 
cent regions, represents the distribution of elevated and depressed areas. 
It is based on actual altitudes and is a rough hypsometric map ; but it is not 
accurate in that sense, because, on the one hand, the number of points whose 
altitude is known is inadequate to accuracy, and on the other, effects of ero- 
sion have been disregarded intentionally. The surface which the contours 
represent constitutes the basins, slopes, ranges, and plateaus as they would 
exist if a plain had been warped and dislocated and had not been eroded. 
The map thus expresses the hypothesis that Asia was reduced to a general 
peneplain and has since been warped in a manner to produce differences of 
elevation exceeding 6,000 meters, 20,000 feet. In the preceding pages and 
in volume 1, part 1, of this publication I have given the facts which indicate 
that, in the districts we observed, the warping has taken place chiefly during 
late Tertiary and Quaternary times. My present purpose is to extend the 
inferences regarding modern mountain growths to regions that are genetic- 
ally related to those which we saw. 

First, with reference to the region of the great alluvial plain of eastern 
China, it is usually recognized that it is an area of depression, a downwarp 
extending from northern Manchuria to Hu-nan and filled with alluvium 
of the great rivers that debouch from the western and southern mountains. 
We have shown that Shan-tung, the peninsula of the Eastern Mountains, 
has since the episode of the early Tertiary faulting stood as a horst in the 
sinking region, its margins being bent down but its interior not notably 
raised in the process.* 

* Research in China, voL i, part I, page 83. 



106 KgSBARGH IN CHINA. 

The eastern margin of this downwarp lies in the Yellow Sea, possibly 
between the point of Korea and Shanghai. The mountains of southeastern 
China may be said to limit it on the southeast. The Yang-tzi defines it 
northeast from the Tung-ting lake. The hills of An-hui and Hu-pei appear 
to be within its area. 

The western margin of the downwarp is the slope of the mountains, 
comprising the Khingan range in the north, the so-called plateau of Shan-si 
in a iqid-stretch, and the mountains of eastern Hu-pei further south. Von 
Richthofen described the limit between the plain and the mountains as a 
fault, which appears on his map, Versuch einer Tektonischen Karte des 
nordlichen Chinas, as the Khingan Linie.* He does not cite any evidence 
of faulting on the line itself, it being drawn indeed in the plain of alluvium ; 
and according to our observations on three different sections the passage 
from the plain to the mountains is a zone of warping, not a line of disloca- 
tion. Where, in latitude 49 , the Siberian railroad descends to the Sungari, 
the eastern slope of the Khingan is a tilted, dissected, but unbroken pene- 
plain. Where the Sha-ho, in latitude 39 , has cut its autogenous valley, 
and the hills about T'ang-hi£n lie half -buried in the plain, the effects of 
modern warping are obvious. Normal faulting, though present in the 
Ning-shan basin, occurred at a remote Tertiary date, and erosion has 
reversed the relief to which it gave rise. Again, in latitude 31 , where the 
Yang-tzi emerges from its profound gorges at I-chang, the mountain slope 
that faces the far-spreading river plain is a tilted surface of erosion, showing 
a continuous stratum of Carboniferous limestone, which toward the base is 
overlain by the K'ui-ch6u red beds in appropriate stratigraphic sequence. 
It is a warped surface, not a fault; and there is no evidence that it is limited 
by a fault at the base. 

This zone of warping was crossed by von Richthofen along two routes 
of travel in Shan-si; the one in latitude 33 , northwest of "Hwai-king-fu;" 
the other in latitude 3 8°, on the great road from T'ai-yiian-fu to the eastern 
plain. In the former traverse he ascended to the plateau over a mono- 
clinal flexure on an erosion surface that is sculptured on Carboniferous 
shales and Sinian limestonesf and that forms spurs between deep gulches. 
The steep slopes of the spurs end in a line and thus simulate a fault-scarp, 
but the structure is that of a simple flexure and is so described by the trav- 
eler. At the more northerly crossing von Richthofen observed step-faulting 
which he describes as follows :% 

After having observed the structure of the mountains in southern Shan<*i, it was 
for me a matter of no slight interest to see in what manner the horizontal strata of the 
plateau might break away or sink toward the Great Plain. As we have seen, the plateau 



♦China, vol. u. f Ibid. t vol. u, p. 407. % Ibid,, vol. n, pp. 440-442. 



THE KHINGAN FLBXURB. 107 

ended mi the south with a short monoclinal flexure. * Were that to be the case in this 
region the plateau must extend far toward the east; but this did not seem probable, as 
according to all accounts I was near the end of the anthracite region. In fact I came 
sooner than I expected to the first fault. The general relation was indeed difficult to under- 
stand in a single rapid traverse, but it was soon clear that the plateau fell off in steps, 
which are occasioned by faults along a great fault zone, which runs from north to south 
and is in part connected with gentle flexures. If one regards the attitude of the strata in 
individual cases, one often finds it confusing, for locally the limestone dips in various 
directions and with different angles. This is particularly noticeable in the descent from 
each separate step. But if one looks back toward the west from a little distance and 
regards the steep slope of the ridge which has just been crossed, one is surprised to observe 
in general only horizontal lines of stratification. In every such case one is on that portion 
of the surface which has sunk down with reference to the higher steps. The variations 
in the altitude of the strata may possibly be related in part to the displacement of the 
beds in the tremendous process of faulting, or may in part be due to caving in, there being 
in some places caverns, which occur especially in the Rauchwacke. 

While these observations are avowedly incomplete and do not carry 
conviction to the reader, the conclusion is not inconsistent with the warping 
observed elsewhere. Warping and faulting are related phenomena; the 
latter is an extreme effect of a concentrated stress set up in consequence 
of the former, and may be looked for wherever the zone between an area 
of depression and one of elevation is relatively narrow as compared with the 
difference of altitude resulting from the movement. 

I conclude that the weight of evidence shows that the passage from 
the depressed region to the elevated plateaus of the mountainous area is 
by a warped surface more generally than by a dislocation, and that the 
"Khingan Linie" is to be regarded as a zone of monoclinal flexure, not as 
a fault. 

The depressed region just described is one of the eastern or outer 
provinces of the continent. While it has subsided somewhat, the region 
on the northwest has risen considerably more. The physiographic record 
shows that up to the close of the Hin-ch6u epoch the difference of altitude 
between the two was no more than that of a gentle, continuous slope, but 
since that time it has been increased to 6,000 or 7,000 feet, 1,800 or 2,100 
meters, on a moderate allowance of 5,000 feet for the elevation of the 
T'ang-hi£n surface in the plateaus of Shan-si, and of 1,000 to 2,000 feet, 
300 to 600 meters, for the depression of the same surface beneath the 
Great Plain. 

This difference in altitude has developed within the late Pliocene and 
the Quaternary; probably chiefly during the latter. There are two con- 
ceptions of the manner: The region which is high may be regarded as a 
horst, which has stood firm while the adjacent area has sunk down below 



I08 RESEARCH IN CHINA. 

its level ; and simultaneously the ocean basins have so deepened that sea- 
level has been lowered 5,000 feet, 1,500 meters. Or, there have been both 
positive and negative movements — not sinking only, but rising also — and 
consequently readjustments of sea-level and of altitudes of various areas. 

The element of time is important in the hypothesis which ascribes 
all epeirogenic changes of level to subsidence in obedience to gravity; but 
the movements in Asia are so recent that time fails. The physiographic 
history of the mountains of Shan-si is plain and consistent. The young 
slopes and scarps and canyons are obvious facts. However we may 
differ in a reasonable estimate of their possible age, we can not assign to 
them an antiquity such that during their development sea-level might 
have sunk 5,000 feet, 1,500 meters. To do so would not only contradict 
the direct evidence of comparison with topographic features elsewhere, 
which are definitely dated by relation to late Tertiary sediments, but 
would require explanation of the absence of a marine record where there 
is an erosion record instead. This question enters into the study of the 
highlands of Asia as a fundamental distinction between two very differ- 
ent interpretations of the orogeny and epeirogeny of the continent. My 
views are more fully stated in the following chapter on the hypotheses of 
continental structure. It suffices here to state that I hold it to be true 
that when some masses sink notably, whether in continental or oceanic 
regions, other masses rise notably; while some parts of Asia have certainly 
subsided during the latest movements, other parts have risen, and the 
upward movements, which are measured by many thousand feet, are greatly 
in excess of the downward movements within the continent. 

The mountainous region of northwestern China may be said to consist 
of the Khingan range north of latitude 40 , where that height is the margin 
of the Mongolian plateau simply, and of the various ranges of Chi-li and 
Shan-si, which as a group are distinct from the Mongolian plateau. Among 
the latter are the Nan-k'ou range northwest of Peking, the Wu-t'ai-shan, 
and the plateau of Shan-si with the Ho-shan. The physiographic history 
of these mountains and the reasons for believing them to have been elevated 
during the Pdn-ho epoch of the Quaternary have been sufficiently set forth. 

Northwest of the mountain system of Chi-li and Shan-si is a depressed 
zone characterized by the basins of Ta-tung-fu, latitude 40 ; of Hin-ch6u, 
latitude 38 30'; of T'ai-yiian-fu, latitude 37 30'; of P'ing-yang-fu, latitude 
36 ; and of the Wei valley, latitude 34 30'. The last stretches far to the 
west, north of the Ts'in-ling-shan, and is related to the depression of Kan- 
ch6u and Su-ch6u, which lies along the northeastern border of the Nan- 
shan. Von Richthofen describes the basin of Ta-tung-fu.* We refer to 

* China, vol. n, p. 359. 



GRABHN O* SHAN-SI. IO9 

our own account of the others in volume 1, except with reference to the 
most northwestern, for which L6czy may be consulted.* 

The zone of these basins, comprising an arc which surrounds Mongolia 
and Ordos on the southeast and which is more than 1,500 miles, 2,400 kilo- 
meters long, is a downwarp with reference to the mountain regions that 
adjoin it. It is related to the heights southeast and south of it by warped 
surfaces, which are, however, faulted throughout considerable stretches, 
producing great scarps several thousand feet high that face inward toward 
central Asia. The ascent toward the northwest or north is generally by 
long, gently inclined slopes, but locally by more steeply tilted surfaces, and 
occasionally by a fault. The O-shan fault in central Shan-si, which defines 
the Fon-ho graben on the west, is the only one which has been definitely 
recognized on that side. 

In its internal displacements the zone of depression is not simple. The 
basins he en echelon and are separated by moderate upwarps that traverse 
the zone diagonally or directly as the case may be. The dividing ridges 
may be enumerated as follows: the Man-t 'o-shan, separating the basins of 
Ta-tung-fu and Hin-chou; the Shi-ling, south of the latter; the Si-yau-ling 
and Si-sin-ling in central Shan-si, between the T'ai-yiian-fu and P'ing-yang- 
fu basins; and the lesser upwarp dividing the Fon-ho from the salt lake 
basin in southern Shan-si. These details of warping are characterized by 
the youthful features of the Fon-ho epoch, namely, the mantle of Huang-t'u 
formation not yet removed, the relation to antecedent streams, and the 
characteristic deep gorges. 

This zone is one of the major structure lines of the continent, which is 
recognized in modern displacements by relatively slight elevation above sea. 
It agrees in general trend with the directions of folding of pre-Cambrian as 
well as of Permo-Mesozoic deformation. It was apparently the littoral of 
pre-Cambrian seas, a strip bordering the downwarps in which the Wu-t'ai 
and Hu-t'o sediments accumulated to great thickness; but after they were 
folded it became part of the land across which the Sinian sea transgressed 
and over which Carboniferous continental deposits more or less generally 
accumulated. During the long quiescence of the continent it does not 
appear to have been a distinctive line ; in the Permo-Mesozoic disturbance 
it was folded; and in the recent extraordinary diastrophism it has again 
become manifest in marked differences of elevation. 

Mongolia lies northwest of the basins of Shan-si and north of the 
depression of Shen-si and Kan-su. It is a region throughout which separate 
ranges rise from great expanses of Pliocene and Quaternary desert waste, a 
region in which the evidences of structure and of physiographic development 

tana— ^••••••a^n^BiBa^^ 

*Rtite det Grafai Sxlchenyi, vol 1, p. 499 «f s§q. 



HO RESEARCH IN CHINA. 

are disconnected. They have not been observed from the point of view we 
are now taking. The available data relating to the structural trends, the 
isolated ridges, the desert plains, and the deep depressions are gathered by 
Suess into a masterly description in the third volume of Das Antlitz der 
Erde. The acute features of dislocation and erosion; the warping of the 
Tertiary Gobi deposits and their occurrence high on the ranges from which 
they extend to basins below sea-level: these suffice to bring the period 
of diastrophism to which the relief is due within the later Tertiary and 
Quaternary. I quote Huntington, who has studied the western part of 
the vast region.* In regard to the Zorabad basin, he says : 

Apparently it was first occupied by the sea and later became dry land. Then, by 
the warping of the earth's crust, it was converted into a lake, which in time was drained 
by the cutting of a gorge. As the water of the lake receded, gravel was washed in from 
the sides and covered the lake deposits. Since that time the gorge at the outlet has been 
cut deeper, the various deposits have all been more or less dissected, and terraces have 
been formed. At intervals during the progress of these events, warping has gone on in 
such a fashion that the size of the basin has continually diminished and all the deposits 
except the most recent gravels have been warped along the edges, although apparently 
remaining horizontal in the center of the basin. Most of this history probably belongs to 
Tertiary times, although the dissection of the lake deposits and the formation of the terraces 
almost certainly belong to the present geological era. 

In order to understand the geological history of Persia it will be necessary to ascertain 
to what extent a similar series of events has occurred in other basins. What few facts 
are known indicate that the history of all the basins is similar to that of Zorabad, with the 
exception of the lake episode. The only lakes of which we have record in the other basins 
occurred at a later time and were due to changes of climate rather than to warping of the 
crust. 

The mountains of Trans-Baikalia constitute a group which is clearly 
distinguished from the Gobi region on the south, the plateaus to the north- 
east, and the plains of the amphitheater of Irkutsk to the northwest. 
Whereas the Gobi is a region of displacement and aggradation and the 
plateaus are one of regional uplift and the plains one of regional depression, 
Trans-Baikalia is characterized by elevation, faulting, and denudation. I 
have already cited the evidence adduced by Suess for ascribing to the basin 
of Lake Baikal a late Tertiary date, and stated that the conclusion may be 
extended to the ranges of Trans-Baikalia. This applies to the principal 
heights in the northeastern district. It is doubtful how far the Tertiary 
uplift may be traced in the adjoining plateau district, where the sharply 
defined canyon of the Lena has the aspect of a Quaternary gorge. I am 
inclined to regard the Trans-Baikal mountains as an insular faulted upwarp, 
like Shan-tung, and to infer that the plateau region is of later elevation. 

* Explorations in Turkestan, Carnegie Institution of Washington Publication No. 26, p. 242. 



WARPING IN CENTRAL CHINA. Ill 

From Siberia we may return to central China. 

The Ts'in-ling-shan rises from the valley of the Wei by a steep warped 
surface and fault-scarp, which we ascribe to the Quaternary (Fon-ho, or 
Yang-tzi) epoch. Among the heights of the range we recognize a mature 
surface, which we attribute to the Ts'in-ling cycle of late Tertiary time. 
It extends beyond the Ts'in-ling range, across the Han watershed to the 
middle Yang-tzi region, and is strongly warped. The great features to 
which the warping gives rise are four: the Ts'in-ling-shan, the Han down- 
warp, the Kiu-lung-shan between the Han and the Yang-tzi, and the present 
basin of Ssi-ch'uan- 

The Ts'in-ling-shan is a long upwarp, the eastern continuation of the 
Kuen-lung; it attains a general elevation of 7,000 to 9,000 feet, 2,100 to 
2,700 meters, and in the special accent, the Ta-pai-shan, rises to 12,000 feet, 
3,600 meters. On the south it sinks to the Han downwarp, which is a broad 
depression having summit altitudes of about 3,000 feet, 900 meters, which 
are modified by local upwarps that probably reach 6,000 feet, 1,800 meters, 
and by two pronounced downwarps, those of Han-chung-fu and Hing-an-fu. 
The floors of these basins are plains of aggradation, that of Han-chung-fu 
approximately 1 ,500 feet, 450 meters, that of Hing-an-fu very nearly 800 feet, 
240 meters, above sea; but the Ts'in-ling erosion surf ace sinks beneath the 
Quaternary deposit, being depressed to a still lower level. At Hing-an-fu 
the coarse gravels, sands, and clays form bluffs along the Han. The Red 
Basin of Ssi-ch'uan is a downwarp like the two mentioned, except that it is 
very much larger, and, as the remarkable delta plain of Chung- t'ing-fu 
shows, is a region of continued subsidence and aggradation. The Kiu-lung- 
shan is an upwarp containing summit altitudes of 8,000 to possibly 12,000 
feet, 2,400 to 3,600 meters. It lies between the basin of Ssi-ch'uan which is 
on the west and the great downwarp of the lower Yang-tzi, its warped sur- 
face passing beneath the flood-plain at I-chang. On the north it is bounded 
by the Han downwarp. Southward it extends across the Yang-tzi, its 
surface declining to depressions that are not yet observed. 

The warped surface of Central China, which may thus be analyzed, 
exhibits differences of altitude of 12,000 feet. It is, so far as we saw it and 
we believe generally, an erosion surface which, while retaining notable relief, 
assumed mature features by the close of the Tertiary period. It may have 
persisted at a low elevation into Quaternary time. During the Quaternary 
it has been warped, giving rise to the great mountain chains and extensive 
basins that now exist. The warping characterizes the Yang-tzi epoch of 
erosion, and the youthful aspect of the canyons of that cycle is the ground 
for the inference that the movement did not assume notable proportions 
until Quaternary time. 



112 RESEARCH IN CHINA. 

The elevation of the Ts'in-ling-shan is continued toward the west by the 
Kuen-lung and the Nan-shan, which rise to much greater heights; but the 
physiographic aspect appears to change. The broad upwarp which, in 
longitude 108 east, is ioo miles, 160 kilometers, across without a break, is 
replaced by several ranges separated by valleys and basins. The effects of 
warping are more complex and are probably accented by faulting. The 
type is rather that of the Gobi than that of central China. 

Tibet and the Himalayas finally claim attention. 

The Alps of eastern Tibet, the Yung-ling, tower above the lowlands of 
Ssi'-ch'uan in wonderful grandeur to an extreme altitude of 7,000 meters. 
We have no definite knowledge of the physiographic aspects of this great 
mountain face, but in one respect it differs markedly from the southern 
front of the Himalayas, with which it may naturally be compared. The 
rivers that drain the Himalayas flow directly across the range, after the 
manner of consequent streams, which have developed at right angles to the 
trend and been extended by headwater erosion in consequence of a com- 
bination of favoring conditions. The rivers of the Tibetan Alps, on the 
contrary, flow southwest between high ranges, which direct them in courses 
diagonal to the lines of shortest descent toward the basin of Ssi'-ch'uan. 
They thus have the character of streams which are consequent upon a 
folded or faulted surface and take their own way down the axial lines of the 
major depressions. There is thus reason to regard this slope as being 
composed of successive upwarps or fault-blocks, which he en echelon and sink 
at their southeastern ends to the lowland of Ssi'-ch'uan. The character is 
expressed in the contours which define the slope north of latitude 30 and 
about the meridian of 103 east. 

Toward the west and south the great ranges of the Tibetan Alps are 
bounded apparently by the broad plateau, which is deeply incised by the 
canyons of the upper Yang-tzi and the Mekong and their several branches. 
The parallelism of these great rivers west of the one-hundredth meridian 
may be an effect of unknown tectonic lines, but it is with equal reason 
explicable as the growth of autogenous canyons on a uniform slope. The 
meanders of the Yang-tzi in latitude 25 north may be attributed to 
capture across a fault-scarp. 

The western part of the map includes the vast highland of Tibet and 
its bounding ranges, the Altin-tagh on the north and the Himalayas on the 
south. The structural character of the plateau is not known, but it appears 
to be that of a mass which has been forced above a position of equilibrium 
and which has consequently broken into blocks that have suffered diverse 
displacements. The depressions are deeply filled with Pliocene and Qua- 
ternary sediments. 



WARPING IN CENTRAL ASIA. 113 

The limiting ranges hold apparently homologous relations to the 
plateaus; but they differ greatly in history and structure. The Altin-tagh, 
occupying part of the northeni Tethys, was folded primarily in the Permo- 
Mesozoic revolution, and its essential structures thus date from a some- 
what remote time. The Himalayas did not suffer compression till the 
beginning of the period of diastrophism that marks the late Tertiary and 
Quaternary. The Altin-tagh seems to rise from the Tarim basin as a con- 
tinuation of the eroded surface which plunges beneath the Gobi deposits 
of the desert; it resembles apparently the warped surface by which the 
Shan-si mountain region sinks beneath the plains of eastern China; and 
though possibly in some sections broken by normal faults, it does not differ 
from other mountain slopes of Asia. The Himalaya range, on the other 
hand, is unlike them. It is separated from the plains at its southern base 
by thrusts of great magnitude, which dip beneath the upraised mass. The 
effect is as if the range were pushed southward — were overthrust ; it may 
equally well be expressed by the statement that the lowlands are pushed 
northward — are underthrust. Since the overthrusting or underthrusting, 
whichever is the dominant fact, involves movement on an inclined plane, 
the mechanical condition is that which would result from driving a wedge 
under the range. Either the range must be raised or the wedge must be 
depressed, or both movements may occur. In discussing the analogous 
case of the Lewis range of the Rocky Mountains in Montana, I have shown 
that an elevation of 3,400 feet is probably attributable to a displacement 
of 7 miles on the flat thrust which underlies the Algonkian strata.* The 
thrusts beneath the Himalayas are apparently even more important factors 
in the relative elevation of the mountain mass. Among Asiatic mountains 
the Himalayas thus present a unique case of mechanical relations. 

The elevation of the Tibetan plateau (Isle Tibet) is apparently an effect 
of the underthrusting, to which we may attribute some considerable part 
of the altitude of the Himalayas. I conceive that the plateau is the surface 
of a deep-seated, strongly compressed sub-Tibetan mass. 

* Stratigraphy and Structure, Lewis and Livingston Ranges, Montana, Bull. G. S. A., vol. xm, p. 345. 



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CHAPTER V1IL— CONTINENTAL STRUCTURE OF ASIA. 



In the preceding chapters the distribution and sequence of rocks of 
successive ages from pre-Cambrian to the present have been discussed, and 
the epochs of marked diastrophism have been distinguished from the periods 
of relative quiescence. The facts are inadequate to a satisfactory discus- 
sion, and one is confronted with the alternative of abandoning any attempt 
at a systematic presentation, or of drawing inferences which are sometimes 
little more than suggestions. Without blinding myself to the uncertain- 
ties of the latter course I have adopted it. 

In drawing inferences on the facts known to me I have been consciously 
governed by hypothesis, which has taken the form of a hypothesis of con- 
tinental structure. In order that the bearing of the latter may be recog- 
nized it is here stated in brief. The test of the hypothesis will come with 
the further development of facts as observations are extended; and ulti- 
mately that which is sound will go toward a better understanding of the 
history of the continent. 

HYPOTHESIS OF CONTINENTAL STRUCTURE. 

i . It is postulated that the . continental mass called Asia is hetero- 
geneous; and that the unlike parts of it are of notable size, varying from a 
few hundred square miles in superficial area to subcontinental dimensions. 
I shall refer to these as elements of the continent, or continental elements. 

2. The distinction between the continental elements is based upon 
their behavior during vertical movements, it being held to be demonstrable 
on the evidences of erosion or sedimentation that certain masses have repeat- 
edly shown a tendency to rise, whereas others have shown a like pronounced 
tendency to subside. The boundaries of the elements are accordingly 
indicated where conditions of general denudation pass into conditions of 
long-continued aggradation, either subaerial or submarine. 

It follows that those continental elements which have tended to rise 
are recognized by the unconformities or absence of sediments resulting from 
conditions of erosion; whereas those elements that have tended to sink 
are recognized by the accumulations of sediments. 

It is desirable to distinguish the two types of elements by their diverse 

tendencies with reference to relative vertical movement, as positive or 

negative. I shall designate those which have tended to rise as positive 

elements; and those which have tended to sink as negative elements. 

115 



Il6 RESEARCH IN CHINA. 

3. It is observed that uplands of erosion and lowlands of aggradation are 
commonly joined by a monoclinal flexure, which in some places involves a 
normal fault. When the region is altogether under subaerial conditions the 
flexure constitutes a warped surface which is a mountain slope. An example 
is found in the present slope from the mountains of eastern Shan-si beneath 
the great plain of China. Or when the sunken region is so situated as to 
become an arm of the sea, the flexure is the locus of a coast line and the 
depressed area becomes a basin of marine sedimentation; such was the 
descent from Gondwana land into the deepening trough, which was the 
southern Tethys and which is the Himalaya range. 

4. It is deemed probable that the continental elements differ in density, 
among themselves and also in comparison with the suboceanic masses ; this 
difference being an original character in the sense that it has inhered in 
the individual masses as far back in geologic history as the record of erosion 
and sedimentation is intelligible. 

5. There have been horizontal movements as well as those in a vertical 
direction. The horizontal displacements are of notable magnitude, and 
their effects are seen in the schistose structures of the once deep-seated rocks 
and the overthrust and folded structures of the more superficial strata. 

6. An effect of horizontal movements has been to crowd the continental 
elements together, and consequently to cause a certain amount of mashing 
in their deeper-seated portions. Just how the shortening may be distributed 
below the superficial crust which we can observe, we do not know, but from 
the universal occurrence of schistosity in rocks exposed by profound erosion, 
it seems probable that the compression is not far from uniform. On the other 
hand, at the surface there are diversities of structure and attitude which 
serve to concentrate the effects of horizontal displacement in certain zones; 
namely, in zones where sedimentary rocks accumulated to considerable 
thickness. 

7. The conditions which concentrate the effects of horizontal thrust in 
zones of sedimentary rocks are: (a) the fact of stratification, which deter- 
mines the arrangement of material in extended sheets that are capable of 
moving over one another and consequently of folding with comparative ease; 
(6) the deflection of such strata from a strictly flat attitude, in such manner 
that initial lines of flexure are established, on which primary anticlines and 
synclines are later developed. This condition results from unequal subsi- 
dence during the process of deposition. 

8. Recalling that coast lines are established along the monoclinal 
flexure which joins a rising with a sinking continental element, and that 
sediments accumulate to greatest thickness usually in a zone parallel to the 



PERIODICITY OF PIASTROFHISM. II.7 

coast, it is seen that zones of folding are commonly coastal zones. Since 
progressive subsidence results in the development of initial dips in lines 
essentially parallel to the coast, and since initial dips determine the axial 
directions of folds during the next epoch of deformation by horizontal stress, 
it follows that the axial directions of folds conform to the general contour of 
the higher continental elements, to the land masses. Furthermore, since 
these elements are the masses against which the strata are pressed in the 
process of folding, they are enveloped by the folds for that reason also. 

Thus the axial directions of folds, the Leitlinien of Suess, constitute criteria 
for the analysis of continental structure that are scarcely second in importance 
to unconformities and deposits. 

9. There is abundant evidence in the broad relations of structure of 
North America, Asia, and Europe to prove that the tangential pressures 
exerted upon the continents proceed directly from the denser submarine 
masses. The theory is here entertained that these pressures are due to 
what may be called suboceanic spread, i. e., to the expansion of suboceanic 
masses, say 100 miles deep, at the expense of subcontinental masses, in 
consequence of the efficiency of stresses due to greater density to direct 
movements occasioned primarily by molecular or mass changes under 
varying conditions of temperature and pressure. The general result is 
plastic flow in rigid and solid rock masses, and it is held that in the great 
suboceanic regions such flow is a persistent condition, to which we may 
ascribe those accumulated stresses that have sufficed to produce the re- 
current pronounced effects of diastrophism. 

10. It is held to be demonstrable, on the evidences of sequences and 
volumes of sediments, that the tendencies toward diverse vertical displace- 
ment of the continental masses have been effective in producing movement 
only at long intervals and during relatively short epochs ; and that between 
those epochs of active displacement the tendencies toward movement were 
ineffective. Hence we may recognize cycles of diastrophism, each one of 
which comprises: (a) a comparatively brief epoch of orogenic and epeiro* 
genie activity, which results in elevated lands and restricted mediterraneans, 
energetic erosion and voluminous terrigenous sediments, and climatic and 
faunal diversities. And (6) a comparatively long period of continental 
stability, which results in extensive peneplanation, meager terrigenous 
sediments and general marine deposits, extended epicontinental seas, and 
climatic and faunal uniformity.* 

♦The evidences of periodicity in earth movements and the effects of periodicity on climates and faunas 
are broadly and exhaustively set forth in the works of the author of the theory, T. C Chamberlin. See 
Chicago Journal of Geology; Manual of Geology, Chamberlin and Salisbury; and Fundamental Problems 
of Geology, in Year Books and publications of the Carnegie Institution of Washington. 



Il8 RESEARCH IN CHINA. 

1 1 . The critical times which bring out continental structure are the 
epochs of diastrophic activity. During the periods of inactivity the dis- 
tinctions between heterogeneous elements become less obvious and may 
become obscured by extended peneplanation and marine transgression. 

The critical epochs for Asia were the mid-Proterozoic, the late Protero- 
zoic, a Siluro-Devonian (?), the Permo-Triassic, and the post-Eocene times 
of diastrophic activity. It is by the distribution of the corresponding sedi- 
ments and unconformities and by the leitlinien that we may analyze the 
continental structure. The distribution of Sinian, Carboniferous, or Cre- 
taceous lands and seas, resulting from static conditions among continental 
elements, is much less significant as an index of structure. 

CONTINENTAL ELEMENTS OP ASIA. 

The criteria upon which we may discriminate continental elements 
depend upon the activities of diastrophism, erosion, and sedimentation. 
Proceeding inductively, we should first note the distribution of sediments, 
next the distribution of unconformities, and finally the arrangement of 
structural lines. This course has been followed in the study of Asia and 
the preparation of the maps that accompany this report, at least in so far 
as the data permit ; but in order that the record of erosion and sedimenta- 
tion should be properly interpreted, it is essential that we should be able to 
define with reasonable accuracy the date of a given unconformity or deposit, 
and where uncertainties exist in this regard the conclusion is necessarily a 
qualified one. Such is unfortunately the fact for very extended areas in 
Asia. The fossils which have been collected are comparatively few. Their 
stratigraphic range is determined only in isolated instances. There are 
large masses of strata assigned doubtfully to the Proterozoic or the Paleo- 
zoic. And thus, even in the broad analysis, provisional conclusions are 
necessary. 

Nevertheless, the general structure of the continent is clearly indicated 
by the leitlinien. Observations of structural trends are possible where 
refined study of sections is not. The attention of European geologists, who 
are the chief contributors to our knowledge of Asia, has been fixed partic- 
ularly on structural phenomena, and Suess has applied his great genius for 
interpretation particularly to the task of ascertaining the structural lines of 
the globe. He has perfected his study of Asia to the fullest extent possible 
on the available data, and his conclusions form the basis of my inferences. 

I proceed to consider some of the results. 

According to Suess, the nucleus of the Asiatic continent (le fatte pri- 
mitif) is that Siberian mass which exhibits two structural trends : the Baikal 
trend, northeast-southwest, and the Saian trend, northwest-southeast; these 



POSITIVE ELEMENTS OF ASIA. 119 

diverge from the southern point of the amphitheater of Irkutsk. Upon 
the basis of these two directions, Suess extends the nucleus southward at 
least to the center of the Gobi district, including in it the Trans-Baikal 
mountains, and far to the northeast to the mountains which bound the con- 
tinent toward the Okhotsk sea. This nucleus is a major positive element 
of Asia, which, throughout geologic history, has exhibited a tendency to rise 
or remain stable and has been equaled in this tendency only by the great 
Canadian shield of North America. It is significant that both of these 
great positive elements adjoin the Polar ocean, a depressed area of compar- 
atively small extent, and during Paleozoic and later times have not been 
subjected to horizontal thrust in any marked degree. As regards the 
bounds of the nucleus of the Asiatic continent on the south and east, I 
would draw them to include the plateau region which appears not to have 
been folded since a very early geologic date ; but I would exclude the zone 
of folded sediments of the Altai and Trans-Baikalia, which represents a 
locus of depression adjacent to the major element. Parallelism between 
the strike of schistosity and the axial trends of adjacent folds is a mechan- 
ical result, which may follow from the masses having been subjected to a 
common pressure or to pressure in the same direction at separate times. 
But the distinction between ancient schists and folded strata is one which 
serves to place the areas of their occurrence on different elements, the 
former belonging to a raised, the latter to a depressed element. 

The Siberian continental element was deeply eroded in an early pre- 
Cambrian time, and consequently was then an area of elevation. It was 
overflowed by the epicontinental transgressions of the Cambrian, Ordovi- 
cian, and Silurian seas, transgressions which were peculiarly wide-spread in 
the far north. From that time to the Tertiary it appears not to have been 
the scene of notable diastrophic movement, whether epeirogenic or orogenic. 
The horizontal attitude of the early Paleozoic sediments, their vast extent 
where, had they been considerably elevated, they must have been eroded, 
and the seemingly moderate deposit of sediment about the margins of the 
continental element, all tend to show that it has been stable. 

* 

Confining our attention at first to the consideration of those elements 
which are most characteristic of a continent, namely, those which have 
exhibited the positive tendency to stand high, we may next consider the 
Mongolian mass. In general terms it corresponds in area with Mongolia 
or what is known as the Gobi province. On the north it is bounded by the 
folded zone of the Trans-Baikal and Altai mountains, which separate it from 
the Siberian nucleus. On the east it extends to the Wu-t'ai district in 
Shan -si, and may be regarded as including Ordos and northern Shen-si. On 
the south its limits are the Ts'in-ling-shan, the Nan-shan, and the Ti£n- 



120 RESEARCH IN CHINA. 

shan. Between the two last-named mountain systems there is a depression 
which connects the Gobi with the Tarim basin, where the boundary of the 
Mongolian element is indefinite. Westward it extends between the Ti£n- 
shan and the Altai, in a peninsula which may represent a small distinct, 
element, and which ends in the mountains of Semipalatinsk. The history, 
of the Mongolian element is less clearly discernible than that of the Sibe- 
rian, partly because so much of the area is covered by desert sands, and 
partly because we do not know the age of the rocks which appear in the 
isolated mountain ranges. Those ranges are, however, made up chiefly of 
ancient gneisses, granites, metamorphosed sediments, and less metamor- 
phosed limestones, all of which are by lithologic similarity connected with 
the pre-Cambrian or early Paleozoic strata. The region appears to have 
been an area of aggradation, either continental or marine, during a part of 
the pre-Cambrian, and to have suffered tangential compression soon after 
the Wu-t'ai epoch, or possibly later. If the limestones which Obrutchov 
calls early Paleozoic are representatives of the late Proterozoic (Hu-t'o) 
system, then the latest transgression to which the region has been subjected 
was of that date ; but if those limestones are in part Sinian, then the region 
was overflowed by the Cambro-Ordovician sea. The descriptions of the 
rocks jxrint to the probability that the former is the case. The final 
deformation by thrust then probably occurred at the close of the Protero- 
zoic, and from that time on to the Tertiary the Mongolian element remained 
a relatively stable one. It seems, however, to have been liable to greater 
elevation than its neighbor on the north, as it is more deeply denuded. 
In the present state of knowledge regarding the area its individuality is 
recognized rather in the leitlinien which bound it than in any adequate 
understanding of its internal history. 

In this connection we should mention the element which is believed to 
exist as the Tarim basin of eastern Turkestan and is defined, by the great 
trends of the Ti£n-shan, the Mustagata, and the Altin-tagh: Its history is 
unknown, except that it comprises episodes of sedimentation represented 
by rocks that are now quartzites and slates and which may be Proterozoic 
or early Paleozoic. 

An apparent continental element which is involved in the mystery that 
the Tibetan people have thrown over their country is that of the elevated 
plateau of Tibet, On the north it is bounded by the Kuen-lung system, 
the zone of the northern Tethys, in which Paleozoic sediments accumulated 
to notable thickness. On the east are the folds of the Yung-ling, the Alps 
of Tibet, trending north-south, and the depression of Ssi-ch'uan, which has 
been low since Cambrian or pre-Cambrian time. On the south is the Hima- 
laya range, the zone of the southern Tethys, which remained a depressed 



NEGATIVE ELEMENTS OF ASIA. 121 

region till well into the Tertiary. It adjoins the northern Tethys about 
the western side of the high plateaus. Tibet is thus surrounded by zones 
which are or, prior to folding, were zones of great depression; and which 
exhibit axial trends that conform to its contour as to that of an element 
which has stood high during critical periods. The evidence that it is such 
an element is sound, as far as it goes; it could only be offset by the presence 
of thick masses of sediments in the plateau, and of their existence there is 
no proof. The presumption is that older strata are wanting beneath the 
Jurassic and Cretaceous. Hence, I conclude that the Tibetan plateau 
region is a continental element which has always tended to stand high. 

Returning now to the Mongolian continental element, we may recall 
that the zone of the Wu-t'ai folding, which bounds it on the southeast, 
was again a zone of disturbance during the Permo-Mesozoic diastrophism. 
During the long interval intervening between that late Proterozoic com- 
pression that caused the deformation of the Hu-t'o system and the Permo- 
Mesozoic stress that resulted in the folding of the Sinian and Carboniferous, 
Mongolia appears to have been connected with a stable mass, which was 
coextensive with northern China. In this region the Sinian limestones are 
succeeded unconformably by the Carboniferous continental deposits; but 
the plane of unconformity is detected only upon observations of slight 
evidences of erosion in the surface of the underlying limestones. 

It appears probable that there is in southeastern China, adjoining the 
present coast between the Gulf of Ton-king and the mouth of the Yang-tzi, 
a mass that was land during much of geologic history; but our knowledge is 
too meager to establish any incident of erosion or overlap. 

And finally, in the peninsula of India is the broad area of ancient pre- 
Cambrian rocks, which, being overlain by Cretaceous strata, represents a 
region in which erosion has more than balanced sedimentation throughout 
practically the whole of geologic history, and which may therefore be 
regarded definitely as a continental element that has long tended to rise. 
It is the essential part of Gondwana land. 

I now take up the zones of subsidence. Before proceeding to describe 
them, I may point out that they differ in form from the nuclei that have 
been described. They are relatively long and narrow; they do not suggest 
masses which have once been rounded and which, in compression, have 
taken on the lenticular form, as do those continental elements ; but, on the 
contrary, seem rather to constitute those portions of a matrix in which 
rounded bodies are embedded. 

The zone which first invites attention is that of the Trans-Baikal, Saian, 
and Altai mountains, which embraces the southern curve of the Siberian 
nucleus. Beyond the fact that it was a region of sedimentation and folding 



122 RESEARCH IN CHINA. 

during pre-Cambrian time, and that it was again the scene of deposition 
during the Devonian, if not during earlier Paleozoic, we know but little 
regarding the history of the zone. Obrutchov and the other Russian geolo- 
gists who have studied the typical Trans-Baikal region distinguish the 
Archean, metamorphic schists, Paleozoic terranes, intrusive and effusive 
rocks, and the Angara series. There is ground for the inference that this 
vast mountain region of northern central Asia includes strata of the Wu-t'ai, 
Hu-t'o, and pre-Cambrian systems, and possibly others which have not 
yet been distinguished ; and that the Paleozoic history may include episodes 
of deformation and erosion other than the transgression of the Devonian sea, 
which is the only one distinctly recognized. The Angara deposits are chiefly 
continental and unconformable to the Paleozoic. 

Next is the zone of the Wu-t'ai-shan. In the sediments which accu- 
mulated in the downwarp to which it corresponds we distinguish with 
certainty a great thickness of very early Proterozoic sediments, the Wu-t'ai 
series, which were intensely deformed and metamorphosed during a mid- 
Proterozoic epoch of orogeny; a later Proterozoic series, the Hu-t'o, which 
represents shore conditions and which was moderately deformed at the close 
of the Proterozoic era; and finally the Sinian and Carboniferous deposits 
which, although part of wide-spread sheets of sediment, were nevertheless 
folded in this zone somewhat more narrowly than in adjacent areas. Here, 
then, is a zone in which there was recurrent deformation at each of the 
episodes of pronounced compression known to us; and it may be noted 
that this zone is parallel to and not far removed from the Pacific ocean basin. 

The zone which next engages our attention is a complex one, repre- 
sented by the principal mountain chains of Central China and Central Asia. 
Beginning in the west, we may assign to it the Altin-tagh, the Kuen-lung, 
and the Nan-shan, the Ts'in-ling-shan, and the Alps of western Ssi-ch'uan, 
and between the two last the depressed basin of Ssi-ch'uan. To this com- 
plex zone we may also assign the region of eastern Ssi-ch'uan and possibly 
the ranges that border the lower Yang-tzi on the southeast. 

The geographic conception which links all of these items together is 
that of the mediterranean sea of Asia, which Suess has called the Tethys. 
It is a sea which prevailed throughout all Paleozoic time in Central China, 
where there is practically an unbroken sequence of sediments from early 
Cambrian to the Permo-Mesozoic. It is probable that its northwestern 
extension in the zone of the Nan-shan, and possibly to the Kuen-lung, was 
also continuously a marine strait from the early Paleozoic on; but in that 
region the presence of pre-Devonian Paleozoic rocks has not been surely 
established in any section. The record of this zone is one of continuous 
subsidence up to the time of the Permo-Mesozoic deformation, when it 




faleinenLr which have shewn a 
dnided txndrrvp to stand high I 



tEl&n&ris vhich hnv* shown 



dMitlnt OndmievtD sink lew* 



I Dirrrtrires vflH^sor 



DIRECTION OF MOVEMENT. 1 23 

became the seat of pronounced folding and finally, in Central China, at least, 
of intense metamorphism and gigantic intrusion. The effects of folding 
and metamorphism appear to have encompassed the basin of Ssi-ch'uan 
on the north and west, and that area has persisted in its tendency to 
subside, up to the present time. 

Finally, we have the peculiar zone of the Himalaya system, extending, 
in the sense in which I use the name, from Burmah to Afghanistan. It is 
characterized by a history of subsidence and sedimentation which, though 
occasionally interrupted, proceeded without folding up to the middle Ter- 
tiary. The unconformities which are assigned to the early Paleozoic and 
the Carboniferous are marked by erosion, but not by discordance. The 
zone is, therefore, one which longer maintained a continuous history of sub- 
sidence than any other of the Asiatic continent. It was the southern branch 
of the Tethys, embracing the supposed island of Tibet on the south and 
separating it from Gondwana Land. In the middle Tertiary the strata 
deposited in it were folded and overthrust, making a mountain range which 
was the antecedent of the present Himalayas. Until the physiography of 
the region shall have been studied, we may not know whether the range 
then attained the elevation we now observe or whether it was later warped 
or thrust to its present altitude. 

TANGENTIAL COMPRESSION. 

The generally schistose, folded, or overthrust structures of the rocks of 
Asia demonstrate the fact of tangential compression. So far as sedimentary 
rocks are affected the structures are conspicuously concentrated in certain 
zones which are arranged in crescents and give the continental structure its 
most obvious characteristic. Nearly all of the crescentic zones are concave 
toward the north or northwest, conforming to the masses of the positive 
elements, according to the hypothesis here entertained. 

The opposing directions of pressure and resistance were radial to these 
crescentic curves; that is, north and south, or northwest and southeast, or 
northeast and southwest. About the eastern end of Isle Tibet they were 
exceptionally east and west. It is perhaps debatable whether the direc- 
tion of movement on these radii was outward from the center toward the 
periphery or inward from the periphery toward the center. The Siberian 
nucleus is the common center about which the crescents are grouped. Has 
the radial movement been outward, has the nucleus moved southward; 
or has the radial movement been inward, have the continental elements 
been forced against the nucleus? 

Certain details of structure, as commonly interpreted, indicate an 
outward, southward movement. They are overturns and overthrusts. In 



124 RESEARCH IN CHINA. 

the Wu-t'ai-shan, Nan-shan, Kuen-lung, and Himalaya ranges the prevail- 
ing direction of overthrows is southeast or south. Regarded as structures 
which have been thrust over they would commonly be attributed to a force 
which caused movement from the north toward the south. Heim first 
showed the fallacy of this reasoning and pointed out that an overturn is 
directed toward the lower foot of an anticline or is controlled by other 
local mechanical conditions.* With reference to the direction of movement 
such a structure may be regarded as overthrust or underthrust; and while 
it is probably true that overthrusting, which takes place toward the surface 
and therefore in the direction of least resistance, is easier than under- 
thrusting, which involves subterranean compression, yet the latter occurs 
when a relatively depressed mass is pushed under a relatively high one. 

As is emphasized by Suess, the Siberian nucleus has been undisturbed 
since a pre-Cambrian date; yet those who would argue for an outward 
radial movement must there find a source of expansive stress. The nucleus 
could not possibly have been the center from which radiated the forces of 
compression that transformed Asia in the Permo-Mesozoic. The folded 
strata of the Altai and Trans-Baikalian ranges were pressed against its 
resistant mass, not it primarily against them. 

The crescentic grouping of compressed structures about Mongolia and 
Tibet and similar masses readily suggests that each such continental ele- 
ment has been a region of expansion producing compressive stresses about 
its margin. It is true that the modern structures of these masses appear to 
be expanded structures, if we may regard normal faulting as evidence of 
extension; but the older pre-Tertiary structures are strongly compressed. 
The evidence we possess, although incomplete, is all opposed to this hypo- 
thetical suggestion, which may be set aside without further discussion, since 
the arrangement which prompts its consideration may equally well be 
explained as a direct consequence of general compression. 

A southward, outward movement of the continental masses would be 
an expansive movement, which, under any arrangement of local stresses, 
would mean enlargement of the continent; but the development of Asia 
has been characterized by repeated pressing together, by welding of discrete 
land masses; the facts of general structure can be explained only as effects 
of a compressive strain, which has proceeded from an extra-continental 
source and which has become effective repeatedly, but at long intervals, 
and yet always in the same directions. 

The extra-continental sources of compressive stress which satisfy the 
conditions of relative position, permanency, and capacity are the Indian 

* Mechan'smus der Gebirgsbildung, vol. I, p. 233. 



PACIFIC VBRSUS ATLANTIC. 12 5 

and Pacific ocean basins. They lie south and southeast from the continent ; 
stresses exerted from them would tend northward and northwestward. 
Their vast depressions have been oceanic basins throughout known history, 
however broadly their margins and connections may have varied. We 
may state this unequivocally, for apart from other reasoning there is no 
conceivable storage place for the enormous volume of their waters in other 
parts of the world had their reservoirs been drained at any time during the 
existence of the known continents. With reference to position and per- 
manence the ocean basins thus satisfy the requirements of potential sources 
of stress. 

Suess has pointed out that the Pacific is surrounded by folded coastal 
districts.* The identity of geologic phenomena throughout its periphery 
is common also to other effects: to metamorphism and vulcanism, to phases 
of epeirogeny and orogeny in general. The likeness extends not only to 
identity of phenomena, but also to approximate coincidence of epochs of 
diastrophic activity. Although our knowledge of many regions is incom- 
plete, it may safely be said that there is a Pacific sequence of geologic events 
which differs in many respects from an equally well-characterized Atlantic 
sequence; or in other words, that the history of western North America 
has more in common with that of eastern Asia than it has with eastern 
North America; and that eastern North America and western Europe are 
more nearly related geologically than either of them is to lands bordering 
the Pacific. 

The close relations of diastrophic effects about each ocean basin and 
the distinctions between separate ocean basins are such that the sub- 
oceanic region must be regarded as the source of the principal diastrophic 
forces affecting the continents. 

I conclude, therefore, that the continent of Asia consists of various 
continental elements which have been forced together by repeated thrusts 
exerted from the Pacific and Indian oceans. The Siberian nucleus has been 
an inert, squeezed mass since an early date. The outlying elements were 
strongly pressed toward it during the middle Proterozoic; they were less 
effectively moved at the close of that era, and again possibly during middle 
Paleozoic time; they were most notably displaced during the almost un- 
equaled Permo-Mesozoic diastrophism, which closed all the mediterraneans 
except the southern Tethys; and the Tertiary-Quaternary thrusts from 
the same oceanic sources have folded the Himalayas and raised not only 
that zone, but also Tibet and other mountain regions of Asia, to unusual 
heights. 

*L* Face de la Terre, vol. u, chapter xu. 



126 RESEARCH IN CHINA. 

Suess, in his synthetic study of the continents, says:* "The whole 
southern border of Eurasia advances in a series of great folds toward 
Indo-Africa." 

With this view the preceding conclusion stands apparently in sharp 
contradiction, but it is not. When a mass of material is spreading by 
plastic flow, as tar spreads, a superficial obstruction causes the surface to 
stop, to fold back, and shear over the mass, which continues to flow under 
it. If the material be stiff enough to maintain visible folds, they are seen 
to be overturned and overthrust outward. The curvature of directrices of 
folds is likewise convex outward. Such I conceive to be the state of the 
continent of Eurasia. What Suess considers an outward advance, I regard 
as a retarded superficial layer, beneath which the deeper mass has been 
squeezed northward into narrower space. 

The view that the suboceanic masses press upon the continental ele- 
ments is inherent in any theory which attributes tangential thrust to iso- 
static adjustment or contraction of the spheroid. Ghamberlin has recently 
most fully set forth the theory of contraction due to loss of heat; he has 
contrasted effects in an inner mass that loses heat and an outer shell which 
temporarily stores it; and he has reasoned in accordance with the fact of 
periodic movements that during very long eras the inner mass accumulates 
stresses which are adequate to produce the major deformations; whereas, 
at relatively short intervals the shell is less markedly deformed by stresses 
which gather in it.f 

The accumulation of stress which leads up to the major deformations 
involves the principle of an arch, the outer shell, 800 miles thick, being 
assumed to constitute such a structure capable of supporting a part of its 
own weight. It is stated by Chamberlin} on computations by Hoskins that 
a dome of continental extent, of crystalline rock capable of sustaining 25,000 
pounds per square inch and weighing 180 pounds per cubic foot, would 
bear only ^ part of its own weight. The postulated conditions are 
favorable for a large, if not a maximum, supporting strength in a thin outer 
shell. If a shell of great thickness be involved, additional strength is 
gained, equivalent to 10 feet of load per mile in depth. But when every 
favorable factor has been weighed, the capacity of the dome is found to be 
but a small fraction of its own weight. A still more important considera- 
tion is that the stability of an arch or dome depends upon the immobility 
of its supporting buttresses, whatever they may be, and in the geologic 
case this stable condition must be assumed to endure for a very long time. 
It would seem to require but slight consideration of the disturbances im- 

*The Face of the Earth, authorized English edition, vol. i, p. 596 

t Manual of Geology, Chamberlin and Salisbury, 1st edition, vol. 1, pp. 517 et s*q.; vol. n p. 128. 

%Ibid. t vol. i, p. 581. 



RIGIDITY AND PLASTICITY. 127 

plied even in that gentle warping which is characteristic of the prolonged 
periods of quiescence, to show that a dome of continental extent loaded 
within a small fraction of its crushing load could not stand. Hence I am 
led to conclude that the dome is not a structure whose effect in accumu- 
lating mountain-forming stresses is of appreciable moment. 

The question may be approached in another way. The shortening of 
the earth's radius that ultimately ensues is a measure of the limit of com- 
petency of the arch, which, up to that collapse, has sustained the stress. 
One mile of shortening of the radius involves 6.28 miles contraction of the 
total circumference. In the Permo-Mesozoic diastrophism the Appalachian 
arc was shortened about 40 miles; i. e. 9 there was, on the above hypothesis, 
a contraction of 6 miles. We do not know the figures for Asia at the same 
period, but they can not be less and probably are much greater. Heim's 
measure of the shortening of the Alps, 75 miles, is still the best estimate 
we have in view of the extraordinary overthrusts now postulated for that 
range; hence, the contraction of the radius in post-Eocene time would be 
12 miles. These are but partial figures deduced from individual ranges that 
chance to have been intimately studied, yet they appear very large. Con- 
traction can not, I think, be credited with so great a shortening concen- 
trated in a particular part of the surface within a relatively brief geologic 
period ; nor can the mechanical principle of the dome be invoked to explain 
the prolonged stability and ultimate great displacements of those arcs of 
the lithosphere which are folded up in these and other mountain chains. 

I am thus led to look to another condition for the principal tangential 
thrust exerted by the suboceanic masses against the subcontinental masses, 
namely, to differences of density, which suffice to direct stresses that follow 
from molecular changes and plastic flow in rigid, solid rock masses. 

Rigidity and plasticity of rocks are conceptions involved in these 
hypotheses. I understand rocks within the earth to be rigid in the sense 
that by virtue of intermolecular attractions they strongly resist deformation. 
Under any stress which is within the elastic limit, they behave as imperfect 
elastic solids do. Under any stress which is applied suddenly, they develop 
that internal friction which is called viscosity of a solid.* But under a pro- 
longed stress, which is sufficient to overcome their internal resistance, they 
flow after the manner of a plastic solid. Plasticity of rocks within the 
earth thus involves the concept of a rigid body which is under a persistent 
stress that exceeds its limit of solidity; and which being thus conditioned 
will flow and continue to flow as long as the slightest excess of stress over 
the limit of solidity exists. Rigidity is a quality due to internal attrac- 
tions and is consequently among other things a function of temperature; 
plasticity is a state which may be induced in any confined rigid body by 

*Treatite 011 the Mathematical Theory of Elasticity, A. E. H. Love, vol. 1, p. 104 



128 RESEARCH IN CHINA. 

external stresses which are adequate and which act continuously through 
long times. The definition of adequate is not determinable in the present 
state of knowledge. Experiments on metals and perhaps a few on rocks 
show that a very small load will cause deformation, t. e., time effect, 
throughout a long period, the end of which has not been determined; this 
may result in permanent set. Thus, a small load, say one-twentieth of 
the breaking load or less, may be adequate; it is, however, safer to assume 
that a differential stress in excess of the breaking load is required to initi- 
ate flow. The condition of any rock mass with reference to rigidity and 
plasticity is thus dependent on temperature, conditions of stress, and the 
period of stress application.* 

Considering rock masses beneath the zone of fracture of the earth's 
crust, and neglecting for the moment the question of temperature, we m ay 
say that they are rigid with reference to limited stresses of brief duration; 
but under the pressures due to gravitation they are plastic with reference 
to long-continued stresses, which are sufficient to overcome their internal 
resistances. 

I appeal to this apparent quality of rocks, according to which, in masses 
of great magnitude, they are plastic as well as rigid; and I postulate that 
tangential thrust is an effect of denser suboceanic masses displacing lighter 
subcontinental masses in consequence of plastic flow. 

To illustrate : It is generally recognized that terrestrial masses whose 
three dimensions exceed a few miles are not firm enough to retain their 
form if they could be left standing without lateral support. If the ocean 
basins should become much deeper than they are, the bases of the continents 
would expand into them ; or, if the continents could be excavated to a depth 
of a hundred miles, the suboceanic masses would spread and occupy their 
sites. Hollows more profound than those of the oceanic abysses are prob- 
ably not possible, on account of the plasticity of rocks in large masses. 

Thus, in consequence of the great magnitude of its component masses 
the lithosphere is liable to plastic flow at a depth below the zone of fracture. 
If we consider a section from the surface toward the center, we pass in a 
short distance through the zones of fracture and of folding into the zone 
of flow. This zone may be described as that in which, under adequate dif- 
ferential stress, rocks change form without rupture. The change of form 
is opposed by their internal resistances, which probably increase in some 
unknown ratio with the pressure. At some depth it would become so great 

* These statements regarding the qualities of solid bodies with reference to rigidity and plastic flow 
have been prepared in collaboration with Messrs. C. E. Van Ostrand and P. £. Wright of the Geophysical 
Laboratory of the Carnegie Institution of Washington. To these gentlemen I am' deeply indebted for a 
clearer conception of the probable state of rocks under conditions beyond direct observation. For defini- 
tions of plasticity, flow, and solidity, see Mathematical Theory of Elasticity, W. J. Ibbetson, p. 170 



ISOSTATIC RELATIONS. 1 29 

as to bring the rocks nearer the ideal condition of a perfectly rigid solid 
body, one whose internal friction is infinity. Thus the zone in which plas- 
tic flow is possible under the differential stresses which the lithosphere may 
accumulate passes down into an interior of high rigidity, in which those 
stresses would be relatively ineffective. This zone of flow, which lies 
between a frangible and flexible crust and the relatively rigid internal mass, 
is the zone of primary tangential stress and motion. 

The lithosphere is heterogeneous. Unlike component masses differ in 
density; they may also differ in plasticity under like external conditions; 
and they no doubt vary individually under varying conditions of pressure 
and temperature. These diversities afford conditions of movement which 
are in part persistent, in part irregular or occasional. Difference of density 
is the condition which localizes those thrusts that have acted repeatedly in 
the same sense, from the same sources, at intervals during geologic ages. 
This may be understood through consideration of the relations of a sub- 
oceanic mass and a subcontinental mass lying adjacent to one another in 
the zone of flow. The suboceanic is somewhat denser, enough so to account 
for the depth of the basin below the continental surface, on the hypothesis 
of isostatic* equilibrium of the two masses, f Both masses, being under 
conditions of pressure with reference to which they are plastic, will tend to 
spread. They are supported below by the relatively rigid interior. They 
mutually press against each other along their contact, but they do not press 
equally; the denser will exert the greater pressure by an amount propor- 
tioned to its greater density. 

The differences of density are not great. I follow HayfordJ in his con- 
clusion that the zone of isostatic adjustment, that is, the zone of flow, is 
from 70 to 100 miles deep. The altitude of continental plateaus above 
oceanic plateaus is somewhat less than 3 miles in general, but this difference, 
regarded as an effect of isostatic adjustment, is the measure of the differ- 
ence of density; the latter, therefore, is from 3 to 5 per cent. 

In the zone of flow we thus have adjacent columns, say 100 miles high, 
of which the suboceanic presses against the subcontinental with a force 
that is approximately 3 to 5 per cent in excess of the mutual pressure due 
to the load of the superincumbent rock taken at the density of the lighter 

♦On Some of the Greater Problems of Physical Geology, Dutton, Bull. Phil. Soc. Wash., vol. xi, p. 53 
Definition of isostasy. 

t Bench t fiber die Schwerkraftsmessungen auf dem Meere, O. Hecker, Nature, June, 1904, p. 104. 
Sitzungsbericht Ak. der Wissensch. zu Berlin, Febr., 1902. Verdnentlichung des k. preuss. geodat. Insti- 
tuts; Neue Folge No. 11, Berlin, 1903. Bericht zum xv Intern. Geodat. Konferenz zu Budapest, 1906." 
Geodetic Operations in the U. S., 1903- 1906, a report to the 15th General Conference of the Intern. Geo? 
detk Assn., by O. H. Tittmann and John F. Hayford, Washington, D. C Reviewed by T. C Chamberlin,_ 
Chicago Journal of Geology, J an. -Feb., 1907. 

%Ibid. t page 10. 



136 RESEARCH IN CHINA. 

mass. The importance of this excess pressure is not in its amount, but in 
its constancy. The force is inherent in the permanent conditions of the 
masses and can not be permanently relieved. It constitutes a persistent 
stress, which, according to theory, may eventually suffice to overcome the 
resistance of the lighter mass, and which certainly suffices to affect the 
direction of movement in case of displacement. 

The periodicity of diastrophic effects may be attributed to four con- 
ditions which, after a prolonged interval, unite in accentuating the differ- 
ence between stress and resistance. The first is molecular rearrangement, 
by virtue of which rocks recrystallizing under stress take on the mineral- 
6gical constitution and particular structure which occupies least space. 
The second is the gradual accumulation of stress through excessively slow 
but unceasing movement in suboceanic sectors. It is conceived that there 
is very slow spreading toward the periphery and consequent accumulation 
of stress. The resisting mass is furthermore unloaded by erosion, and herein 
lies a third important disturbing effect, though not a primary cause of 
diastrophism. The fourth condition of periodic movement inheres in the 
storage of heat in an outer shell, as deduced by Chamberlin,* the effect 
being generally to lower the internal resistances of the masses and promote 
the tendency to plastic flow, and locally to induce special conditions of 
melting and extrusion. More or less effective combinations of these effects 
appear to be inherent in the heterogeneous structures of the lithosphere and 
to be adequate to account for the diversities of local diastrophism as well 
as the universality of deformation during the great epochs. 

The development of a particular diastrophic cycle may be suggested as 
follows : Consider the vertical surface or zone of passage from a suboceanic 
to a subcontinental segment to the depth of a hundred miles, more or less, 
below sea-level. Assume that in this vertical zone there is ideally perfect 
isostatic equilibrium, such that upon any deeply buried unit cube the 
pressures will be in hydrostatic balance. To produce mass motion any 
differential stress must, perhaps, develop beyond the breaking load of the 
material. Let it be further assumed that through variation of general 
pressure or temperature or both, there is disturbance of chemical equilib- 
rium resulting in recrystallization and rearrangement of mineral particles. 
Then in the readjustment of any two molecules or particles a strictly local 
rearrangement may take place without bringing about any general move- 
ment; but if the molecular rearrangements occur in the zone of contact 
of two adjacent masses, one of which is denser than the other, the net 
rtsult of all the movements will be from the denser toward the lighter under 

♦Manual of Geology, vol. i, p. 539. 



CONDITIONS OP MOTION. 131 

the directive influence of the heavier. There will thus be established a 
stress or tendency to flow which in course of time may become sufficient 
to overcome the resistance of the solid rock and occasion actual flow from 
the suboceanic toward the subcontinental mass. It is conceivable that 
this molecular process is only one of several which may give rise to a 
similar movement, but in view of the rearrangement of minerals in the 
development of flow cleavage* in deep-seated rocks, recrystallization is a 
process of notable potency and appropriate orientation. 

If once the equilibrium be disturbed to the point of flow the direc- 
tive effect of the stress due to differences of density will lead to extension 
of the suboceanic and compression of the subcontinental segment, with the 
result that accented differences of elevation of the oceanic and continental 
plateaus are brought about. These differences will increase till they balance, 
or overbalance, the energy of plastic flow. The movement will then be 
checked and a reaction will set in which will be propagated backward from 
the continent toward the ocean. The distance outside the elevated area 
to which it will affect the suboceanic mass depends upon unknown factors, 
but it seems improbable that the reaction would check the onward flow 
throughout as much of the suboceanic segment as had been set in motion. 
This conclusion would seem to follow from consideration of the moderate 
stress of reaction as compared with that of original displacement and of the 
higher rigidity of the rocks, as well as of the times involved in the move- 
ments. It is possible that an oscillating motion of long period might be 
established in a certain zone marginal to the continental mass. 

It is important, however, to lay emphasis on the probability that the 
suboceanic spread would not be fully checked. In so far as it continued 
it would constitute an effective condition of accumulating stress, competent 
after a longer or shorter interval to bring about renewed molecular and 
mass deformation. This is, I think, a factor of prime importance, which 
may be regarded as an existing condition, perpetuated since an early stage 
of the earth's history as a solid globe of the present dimensions. 

A major effect of continental elevation is erosion and the transfer 
of notable masses from one part of the surface to another, from a higher 
to a lower area. In considering the influence of this well-known process on 
isostatic equilibrium we must take account of the seeming fact that the 
continents may be sur-elevated in course of energetic diastrophism, and 
the transfer of part of their mass to depressed areas may therefore tend 
toward a just balance; but the reduction of a highly elevated continent 
to a peneplain involves the transfer of loads which may fairly be credited 

♦U.&O. S. Bull. 239, Rock Cleavage, Leith. 



132 RBSBARCH IN CHINA. 

with an unbalancing effect. Opinions will differ as to the importance of 
this factor. In my judgment it is secondary to the prime factor of sub- 
oceanic spread. 

The fourth variable among the influences under consideration is tem- 
perature. Chamberlin's deduction, above referred to, is dependent on the 
accretion hypothesis of the growth of the earth. If it be true, there is a 
marked periodicity in storage of heat in the outer 800 miles of the spheroid 
and the outflow of heat to the surface. That the corresponding variations 
of temperature should have notable effect on molecular rearrangements 
and plastic flow of rocks is according to sound theory and observation. 
That such changes should periodically promote the movements described 
above seems highly probable. 

The intensity of the tangential stress at any depth below the zone of 
fracture is a direct function of the gravitational pressure and an inverse 
function of the internal resistances. It must increase from the surface 
downward with the pressure, but not so rapidly, probably, as the resistances, 
which, therefore, will ultimately neutralize it. The ratios of these functions 
are unknown and the curve of the intensity of the stress in a vertical plane 
can not be calculated. But we may say that the stress will be zero near the 
surface, will increase in the zone of flow to a maximum, and will decrease to 
zero toward the bottom of the zone of flow, i. e., at 100 miles more or less 
below the surface. 

The direction of thrust will be from the denser toward the lighter mass 
in general, but not strictly in a tangential path. In homogeneous material, 
against uniform resistances, the direction would be perpendicular to the 
curve of intensity of stress in a vertical plane ; namely, diagonally upward 
in an upper zone, horizontal at the level of maximum stress, and diagonally 
downward below that level. Among the heterogeneous masses of the litho- 
sphere, affected by minor differences of density, by variations of tempera- 
ture, by schistose or massive or stratified structures, and by inequalities of 
the surface, the local directions and effects of the tangential thrust may be 
extremely variable. 

As applied to Asia this tangential stress may be conceived to have acted 
to compress that portion of the lithosphere lying north of the Indian and 
northwest of the Pacific oceans, with the effect of forcing it northward and 
northwestward. The Siberian nucleus is a portion of that north polar region 
which comprises also Russia, Greenland, and the Canadian shield, and against 
which the stress has been exerted from denser masses of more southern 
latitudes. The sources of the stresses are some of them remote, some of 
them near, as is readily seen by a glance at a map of the northern hemi- 
sphere, but the stresses converge toward the polar lands, where Archean 



TBST OF HYPOTHESIS. 133 

rocks are more generally exposed than anywhere else on the spheroid. Act- 
ing most effectively, we may say, in a zone 20 to 50 miles below the bottom 
of the ocean, the stress has forced all the continental elements of Asia 
toward the Siberian nucleus. The portion lying relatively near the surface 
has not shared equally in the pressure, but has been carried against the cen- 
tral nucleus and folded back from it. The interior chains formed first and 
the outer ones successively, one outside of another; at least such seems to 
be the sequence from the northern Mongolian to the northern Tibetan and 
to the Himalayan folds. And yet each older zone of folding was affected in 
later successive epochs of diastrophic activity, as is evident in the Wu-t'ai- 
shan, where the middle Proterozoic deformation was the most intense, and 
the late Proterozoic and Permo-Mesozoic compressions each weaker in turn. 

The existing unusual elevation of central southern Asia appears to be 
due to compression of the subcontinental mass between the already com- 
pressed Mongolian element and the expanding suboceanic mass of the 
Indian ocean. Gondwana land, the positive continental element of the 
Indian Peninsula, has been carried northward with the deep underflow, 
and the effect of underthrust at the base of the Himalayas is the latest 
expression of the oceanic pressure. 

In closing, it is well not to lose sight of the fact that this chapter is one 
of hypothesis. The analysis of Asia into continental elements, the inter- 
pretation of successive geographic conditions, the attempt to explain the 
arrangement of the leitlinien, and the statement of a source of tangential 
thrust are contributions to theory. They are, so far as I can now judge, 
consistent with the known facts, but they must stand or fall quantitatively 
and qualitatively by the test of the great host of facts which are yet to be 
gathered in the wonderful continent. 



INDEX. 



FAOB. 

Alps, shortening of, by diastrophism 127 

Altai mountains, remnant of Cretaceous-Tertiary 

peneplain near 101 

zone of sedimentation in 121 

Ahin-tagh, structure of 1 13 

zone of deposition in 122 

Alveolitis 57 

Amplexus 57 

Amur, plain of, features of 100 

Angara series, age and character of 80-83 

Appalachian mountains, a type of structure and 

physiography 104 

shortening of, by diastrophism 127 

Archean, definition and use of term 2 

Archean rocks, character of 2, 3, 4, 24-25 

See also T'ai-shan complex. 

Asia, continental elements of 118-123 

continental structure of 1 15-133 

systematic geology of 95-1 13 

mediterranean sea in 80, 122 

mountain chains in, order of elevation of 133 

nucleus of 118-119 

physiographic history of 95-1 13 

str u ct u re of 1 15-133 

AtryPa reticularis 57 

Augen-gneiss, occurrence of 5 

AuloPora rePens 53 

Axial directions of folds, structure interpretable by 117 

Baikal, Lake, depression occupied by, character and 

age of 98, 110 

Baikal trend, course of 25 

Barun Ula range, rocks of 21 

Bassler, R. S., cited on Paleozoic fossils from China 56 

Blackwelder, Eliot, Carboniferous fossils found by . 56 

cited on Tainan limestone 43 

cited on Yung-ning sandstone 12-13 

Ta-yang limestone measured by 9 

Bogdanovitch, K. I. , cited on Paleozoic diastrophism 

in Tibet 66 

quoted on geology of Central Asia . . . . , 63 

Burmah, Carboniferous limestones in 74 

Cambrian fossils, occurrence of, in India 49 

Cambro-Ordovician rocks. See Sinian system. 

Carboniferous fossils, occurrence of 56, 61 , 72, 74 

Carboniferous rocks, character and distribution of 71-76 

occ u rrence of, in Central Asia 61 

unconformity below 67-69 

Chamberlin, T. C, cited on earth stresses 126 

cited on temperature as a factor in diastrophism 130 

Ch'ang-hia oolite, character and distribution of . . . 41 

Ch'ang-Iriu-hien, quartzites near 13 

Ch'au-mi-tien limestone, character and distribution 

of 42 

section of 10 

Chau-tien, Permo-Mesozoic rocks near 86 

CM-li, section in 11-12 

Sinian rocks in 43 

Co mp ression (tangential), effects of, in mountain 

building 104 

discussion of 123-133 

intensity of, at different depths 132 

Conglomerates, intraformational, oc c u r r en ce of 41-42 

Continental elements of Asia, definition of 115 

discussion of 118-123 



PAOB. 

Continental structure, hypotnesis of 115-118 

negative elements of 115 

positive elements of 115 

Cretaceous period, events of 95-96 

Cretaceous-Tertiary peneplain in northern Siberia, 

remnants of 101 

CryPtoMoan Proliferum Hall, range of 9 

CyathophyUum 57 

CyPricardinia lamellosa PhiU 58 

Datta, P. N., cited on Devonian rocks of Asia 65 

Davis, W. M. , quoted on peneplanation in Tien-shan 1 02 

Deformation, dates of 90 

See also Diastrophism. 

Devonian fossils, occurrence of 57, 58, 65 

Devonian rocks. See Siluro-Devonian rocks. 

Diastrophism, critical epochs of 118 

cycles of 117-118, 129-131 

definition of 24 

middle Paleozoic 66-69 

periodicity of 130-131 

Permo-Mesozoic 89-93 

pre-Cambrian 29-31 

pre-Sinian 24-31 

post-Sinian 49-51 

sources of forces of 1 24-133 

Dielasma (cf. saceulus) minimum n. sp 58 

Dikelocephahu sp 49 

Earth movements, character and effects of 116 

periodicity of 117-118, 129-131 

Elevation and depression produced by warping, map 

showing, reference to 105 

Epeirogenic, definition of 24 

Eperiogenic movements. See Diastrophism. 

Erosion, effects of, in diastrophism 130, 131 

Eruptive rocks, occu r rence of 83 

Faulting, relation of warping to 107 

See also Deformation. 

Favosites cervicomis Goldi 58 

Favosiies forbesi 57 

Folding, axial directions of, structure interpretable 

by 117 

elevation by 104 

Permo-Mesozoic 89-93 

Proterozoic 26 

sources of stresses producing 125- 128 

zones of, coincidence of with coast lines 117 

See also Deformation; Diastrophism. 

Fong-huang-shan, pre-Sinian rocks in 14 

Fdn-ho stage of physiographic development, age 

and general features of 99, 103. 105 

Fossils, Carboniferous 61 , 72 

Devonian 57, 65 

Paleozoic 6* 

Silurian 56, 57 

Triassic •* 

Fu-chou group, stratigraphic equivalents of 43 

Fuchs, Edmond, and Saladin, Edouard, cited on 

rocks of Indo-China 23, 92 

Fu-niu-shan, rocks in 14-15 

See also Ts'in-lffig-shan. 

Fusulima cyUmdrica 53 

Futterer, Karl, stru c tur al lines deed from 89 



II 



INDBX. 



PAOB. 

Gilbert, G. K., cited on use of term diastrophism 24 

Giraldi, Giuseppe, fossils collected by 57 

Girty, G. H., Paleozoic fossils studied by 56 

quoted on Permian (?) fossils 84 

Gramsi sandstone, character and distribution of . . . 95 

Glacial deposits, Paleozoic, occurrence of 39-40, 47-48 

Gobi province, continental nucleus in 1 19-120 

physiography of 110 

Gondwana land. Paleozoic diastrophism in 66 

Gondwana series, distribution of 80-81 

Great Plain of China, physiographic history of 

105, 106, 107-108 

Griesbach, C. L., cited on Cambro-Ordovidan rocks 46, 47 

cited on Carboniferous rocks in the Himalayas 74 

cited on distribution of Giumal sandstone 95 

cited on Tertiary history of Asia 96 

cited on Vaikrita system 23 

quoted on Cambrian and pre-Cambrian rocks 

of India 46-47, 48 

Haimanta system,' character, thickness, and dis- 
tribution of 46-47, 48-*9 

Holy sties caienularius 57 

HalysiUs ca U n u latus 64 

Han River valley, Carboniferous limestones in ... . 73 

Jurassic rocks in 88 

Hayden, H. H., cited on Cambro-Ordovkian rocks 46 

dted on intrusive rocks in Tibet 92 

cited on Paleozoic geology of the Himalayas 65 

cited on Paleozoic rocks of India 48-49 

cited on Tertiary history of Asia 96 

cited on Vaikrita system 23 

quoted on Cambrian and pre-Cambrian rocks 

of India 48-19 

Hayford, John P., dted on depth of zone of flow. . 129 
Hdin, A., dted on contraction of Alps by diastro- 
phism 127 

dted on overthrusts 124 

Hei-shui series, rocks of 59 

HHiolxUs 57 

Himalayas, altitudes and general features of 1 12-1 13 

Carboniferous rocks in 74 

Devonian rocks and fossils in 65 

direction of overthrust in 123 

elevation of, date of 96 

pre-Sinian rocks of 23 

zone of deposition in 123 

Hin-chou basin, character and history of 108-109 

Hin-chou stage of physiographic development, age 

and character of 99,103 

Hing-an-fu, Carboniferous limestones near 73 

Holland, T. H., quoted on Paleozoic glacial deposits 

in India 47-48 

Ho-nan, pre-Sinian rocks in 14-15 

Ho-shan, antiquity of 27 

Hsiung-shan, rocks of 15 

Huang-t'u formation, character and origin of 99 

Huntington, Ellsworth, quoted on Zorobad basin . . 110 

Hu-pel, Sinian rocks of 43, 44 

Hu-t'o, origin and use of name 3 

Hu-t 'o system, correlation of 7 

distribution of 7 

rocks of 4, 7, 8 

sediments forming, sequence of 28 

stratigraphic equivalents of 28 

subdivisions of 4, 8 

thickness of 28 

unconformity above 8, 29 

unconformity beneath 4, 7 

Hu-t'o period of orogeny, age of 28 

Hwo-lu-hsien, section near 11-12 



PAOB. 

India, Cambrian fossils of 49 

continental element in 121 

older rocks of 23 

Paleozoic glacial deposits in 47-48 

Indian Ocean, a potential source of compressive 

stress 124 

Indo-China, pre-Sinian rocks of 23 

Intrusive rocks, occurrences of 24-25, 26. 91 . 92 

Irkutsk, remnant of Cretaceous-Tertiary peneplain 

near 101 

Ja-ch6u, folding near 93 

Jenissel, remnant of Cretaceous-Tertiary peneplain 

near 101 

Jurassic rocks, occ ur r en ce and character of 64-65, 86-88 



Carpathian mountains, a type of structure and 

physiography 104 

Kayser, Emanuel, Devonian fossils described by. . . 65 

Khingan Linie, location of 106 

structure along 106, 107 

Ki-ch6u limestone, stratigraphic equivalents of 

King, Clarence, dted on antiquity of mountain 43 

ranges of the United States 27 

Ki-sin-ling lime s tones, age of 45 

character and distribution of 44,45 

conglomerate at base of 

fossils from 

stratigraphic equivalents of 43 

type locality of 

upper limit of 

Ki-tan limestone, character, thickness, and fossils of 53-54,72 

occ ur r en ce and distribution of 71-73 

stratigraphic equivalents of 54 

Kiu-li-shan, rocks in 14-15 

Kiu-lung group, character and distribution of 40-42 

faunas of 40 

section of 10 

stratigraphic place of 37, 43 

type locality of 40 

Krasnoyarsk, remnants of Cretaceous-Tertiary pene- 
plain near 101 

Krapotkin, P., quoted on Stanovoi range 101 

quoted on Vitim plateau 101 

Kuan-yuan-hien, Jurassic rocks near 88 

Permo-Mesozoic rocks near 86 

unconformity near 93 

Kuen-lung range, antiquity of 27 

direction of overthrust in 123 

folding in, date of 96-97 

physiographic aspects of 112 

rocks of 27 

zone of deposition in 122 

Kui-cbou series, stratigraphic equivalents of 84 

Kung-sun-shan, metamorphic rocks on 13 

Ku-shan shale, conglomerates on 41-42 

oc cur r en ce and character of 41 

Lapparent, A. de, dted on relations of Paleozoic 

of Turkestan 64 

LaTouche, J. D., dted on Devonian rocks of Asia. 65 

Ldtlinkn, definition of 25 

value of, as criteria for analysis of continental 

structure H7 

Lewis range, a type of structure and physiography 104 

Liau-tung, sedimentary rocks in 12 

Sinian rocks in 43 

stratigraphic sequence in • 68 



INDEX. 



Ill 



PAGE. 

Loczy, Ludwig von, cited on Carboniferous lime- 
stone 73, 74 

cited on flint laminae in Nan-shan sandstone 

of Tibet 9 

cited on Jurassic events in Asia 97 

cited on Jurassic rocks of Asia 64 

cited on Lo-pan-shan 69 

cited on Paleozoic rocks 59-60 

cited on Permian or Triassic rocks 85 

cited on Permo-Mesozoic rocks 86 

cited on pre-Sinian rocks of Central China . . 13 el seq. 

cited on Sinian system 45 

fossils collected by 65 

quoted on crystalline rocks of Tibet 20 

quoted on Devonian strata in Shen-si 58 

quoted on Jurassic rocks 87, 88 

quoted on Paleozoic limestones 22 

quoted on Permian or Triassic rocks 85 

section cited from 75-76 

Loess basins (northern), altitude of 3 

rocks of 3 

Lorenz, Tbeodor, cited on Tsi-nan limestone 43 

Lowlands, monoclinal flexure defining 116 

persistence of 115 

Lu-shan schists or slates, age of 45, 53 

Man-t'o shales, calcareous layers in 38 

character, thickness, and distribution of 37-38, 43 

conditions of deposition of 38-39 

fauna of 39, 40 

section of 10 

stratigraphic place of 37, 43 

Margerie, B. de, cited on rocks of Indo-China 23 

Martelli, Alessandro, fossils described by 57 

Matsu limestone, age of 53 

Maulmain group, limestones in 74 

Aiegalodon (sp.) v. Pachydomusi sp 58 

Mesozoic, transition to, from Paleozoic, events of . . . 77-88 
See also Permo-Mesozoic . 

Metamorphic rocks, areas of, beyond China 20-23 

Mongolian element of Asiatic continent, limits of 

119-120,121 
Mount. See distinctive name. 



Nan-king grits, character of 53 

Nau-k'ou, term available for system name 3,11 

Nan-k'ou period of orogeny, age of 28 

Nau-k'ou range, section across 10 

Nan-k'ou system, marine origin of 12 

stratigraphic equivalents of 28 

Nan-shan, name suggested for Hu-t'o system 3 

Nan-shan range, Carboniferous limestone in 73 

direction of overthrust in 123 

igneous intrusions in 92 

physiographic aspects of 112 

zone of deposition in 122 

Nan-shan sandstone, character and distribution of. 21 

unconformity above 74 

Nan-t'ai, Wu-t'ai rocks on 5 

Nan-t'ai group, distribution of 5 

rocks of 4,5 

stratigraphic place of 4, 5-6 

structure of 5 

unconformities above and below 4 

Nan-t'ou tillite, character and distribution of 39-40 

stratigraphic equivalents of 43 

Ning-kiang-chdu, section near 56-57 

Ning-shan basin, faulting in 98, 106 



PAOB. 



Obolus asiatica 

Obrutchov, V. A., cited on Carboniferous limestones 

in Tibet 73, 74 

cited on geology of Central Asia 60 

cited on pre-Sinian rocks of Central China . . . I3etseq. 

cited on rocks of Potanin range 21 

cited on Trans-Baikal region 121 

quoted on Archean rocks of Barun Ula range ... 21 

quoted on Devonian rocks of central Asia 62-63 

quoted on geology of central Asia 63 

quoted on Paleozoic rocks of central Asia 61-62 

quoted on rocks of Richthofen range 21 

Ocean basins, a source of diastrophic stresses 125—133 

rocks beneath, greater density of 129 

Oldham, R. D., cited on age of elevation of the 

Himalayas 96 

cited on rocks of India 23 

Olenus sp 49 

Oolitic limestone, occurrence of 45 

See also Ch'ang-hia oolite. 
Ordovician. See Cambro-Ordovician. 

Orogenic, definition of 24 

Orogeny, periods of, in China 28 

Orthis calligramma 56 

Orthoceras 57 



Pacific Ocean, a potential source of compressive 

stress 124 

folded coastal districts surrounding 125 

Pai-shui-kiang, Carboniferous rocks near 73 

Devonian rocks and fossils near 58, 73 

Paleozoic era, diastrophism during 66-69 

early, rocks of 35-51 

late, rocks of 69-93 

middle, rocks of 53-69 

transition to Mesozoic from, events of 77-88 

glacial deposits of, 47-48 

Paleozoic rocks, Nan-shan range 22 

Siau-ho 16 

general discussion of 35-93 

Pd-fai, altitude of 3 

Si-t'ai rocks on 6 

Pef-t'ai peneplain, character, age, and altitude of . . . 101-102 

dissection of 103 

features of 99-100, 100-101 

Pentamerus brevirostris Phill 58 

Permian. See Permo-Mesozoic; Permo-Triassic. 

Permo-Mesozoic diastrophism, discussion of 89-93 

Permo-Mesozoic rocks, discussion of 77-88 

Permo-Triassic rocks, discussion of 80-86 

P'ing-yang-fu basin, character and history of 108—109 

Pleistocene period, deformation during 96-113 

Powell, J. W. , cited on use of term diastrophism .... 24 

Potanin range, rocks of 21 

Pre-Sinian diastrophism, effects of 24-34 

Pre-Sinian rocks, central China, character and dis- 
tribution of 13-20 

Pre-Sinian unconformity, discussion of 31-34 

Productus 74 

Productus semireticulatus 54 

Productus striaius 61 

Proterozoic era, cycle of erosion at close of 31-34 

rocks of 3—34 

PtychoParia, horizon of 49 

Pumpelly, Raphael, cited on Devonian rocks of 

China 54 

cited on Permo-Mesozoic rocks 84 

cited on Sinian system 35 



IV 



INDEX. 



PAOE. 

Rhjetic rocks, occu r rence of 65 

Rkynckonella alinensis 61 

Richthofen, P. von, cited on Carboniferous rocks 71, 75 

cited on cherty limestones near Nan-k 'ou range 1 1 

cited on Devonian rocks of China 53 

cited on Ho-shan range 27 

cited on Jurassic rocks 88 

cited on Khingan Linie 106 

cited on Kuen-lung divide 27 

cited on metamorphic rocks in Shantung 13 

cited on orogenic epochs in China 27-28 

cited on Permian or Triassic rocks 85 

cited on pre-Sanian rocks of central China. ... 13 etseq 

cited on sedimentary rocks of Liau-tung 12 

cited on Sinian system 3, 11,35, 45, 67 

cited on Wu-t'ai system 4 

cited on Yung-ning sandstone 12 

quoted on cycle of erosion at close of the Pro- 

terozoic 31-32 

quoted on Devonian rocks of China 53 

quoted on Permo-Mesozoic rocks 83 

quoted on pre-Carboniferous unconformity. .. . 68 
quoted on pre-Sinian rocks of the Ts'in-ling- 

shan 17-18 

quoted on Sinian system 36-37, 45 

quoted on structure in Shan-si 106-107 

sections quoted from 10, 11-12, 56-57, 82 

Richthofen range, rocks of 21 



Saian mountains, zone of sedimentation in 121 

Saian trend, course of 25 

Saladin, Bdouard, and Puchs. Bdmond, cited on 

rocks of Indo-China 23, 92 

Sang-hu sandstone, stratigraphic equivalents of 84 

Sarawschan range, fossils from 64 

Sedimentary rocks, concentration of effects of thrust 

in, conditions determining 116 

8hang-ho-miaa, Nan-t'ai rocks near 5 

Shan-si, Carboniferous rocks in 75 

graben of 109 

Jurassic rocks in 86-87 

mountains of, physiographic history of 108 

pre-Sinian rocks in 14 

section in 82-83 

Sinian rocks in 43-44 

Shan states, Devonian strata in 65 

Shan-tung, Carboniferous rocks in 75 

depressed region around, physiographic history 

of 105, 106, 107-108 

faulting in 97-98 

Jurassic rocks in 87 

metamorphic rocks in 13 

Permo-Triassic strata in 81 

Sinian rocks in 43 

stratigraphic succession in 2 

structure in 105-106 

Shea-si, Carboniferous limestone in 73 

Devonian rocks and fossils noted in 58, 59 

Shl-ts'uan-hien, Jurassic rocks at 88 

Permo-Mesozoic strata near 86 

ShI-tsui series, rocks of 4 

stratigraphic place of 4 

unconformity above 4 

unconformity below 4, 5 

Siau-ho, Paleozoic rocks on 16 

Siberia, nucleal character of. in Asiatic continent . . 1 18-1 19 

Cretaceous-Tertiary peneplain in 101 

Si -ho limestone, thickness and fossils of 53 

Silurian fossils, identification of 56, 57 



paob. 

Siluro- Devonian rocks, discussion of 53-59 

Sinian, the name and its application 35-37 

Sinian epoch, diastrophism following 49-51 

Sinian limestone, character of 67 

Sinian system, definition of 35-36 

discussion of 35-49 

features of 35-37 

formations composing 37 

glacial deposits in 39-40 

rocks of 32 

summary of observations concerning 43-49 

unconformity above 67-69 

unconformity beneath 8, 29, 31, 35-36 

Sinian, lower. See Man-t'o shale. 

Sinian, middle. See Kiu-lung group. 

Sinian, upper. 5m Tsi-nan limestone. 

Sin-t 'an formation, age, character, and thickness of 55-59,81 

stratigraphic place of 44 

Si-t'ai, Wu-t'ai rocks on 5-6 

Si-t'ai group, distribution of 5 

rocks of 4, 5-6 

stratigraphic place of 4. 5-6 

structure of 6 

unconformities above and below 4 

Spirifer 74 

Spirt fer anosoffi 61 

Spirifer eUgans 61 

Spirifer radiatus 56 

Spirifer (cf. conalifera) Valen 58 

Spiti, India, Paleozoic rocks of 48-49 

Sal-ch'uan. Carboniferous limestone in 73-74 

Devonian rocks in 54, 59 

intrusive rocks in 92 

Jurassic rocks in 87 

Paleozoic rocks in 56 

Sinian rocks in 43, 44 

zone of deposition in 122 

Stose, G. W., cited on flint lamina; in Cambrian 

limestones of Appalachian valley. ... 9 

Stress (tangential), direction of 132 

intensity of. at different depths 132 

Stromatopora sp. indet 58 

Structural lines, map showing, r efere n ce to 89 

Set also Leitlinien. 

Structures, folded, relation of to altitude 104 

Suess. Bdouard, cited on folding in Eurasia 124 

cited on geology of central Asia 63 

cited on leitlinien of Archean rocks in Asia 25 

cited on nucleus of Asiatic continents 118 

cited on permanency of Siberian nucleus 124 

cited on Permo-Mesozoic diastrophism 89 

cited on structure of Asia 1 10 

quoted on diastrophism 24 

quoted on geology of central Asia 60-61 

quoted on Paleozoic rocks of central Asia 62 

quoted on plain of the Amur 100 

quoted on rocks of To-laf-shan 62 

structural lines given by, map showing, refer- 
ence to 89 

SQ-kia-pa, fossils found near 54, 55 

section at 54-55 

structure near 54 

Sung-shan, rocks at and near 14-15 

Switzerland, structure in. as affected by diastrophism 1 27 



Ta-ho formation, age of 45, 53 

T'ai, Mount, location of 8 

T'ai-p'ing. stratigraphic sequence in 62 



INDEX. 



PAOB. 

T'ai-shan complex, correlation of 2 

lithologic characters of 2,3,4, 24-25 

structural characters of 3 

type locality of 2 

unconformity above 1, 4, 5, 9 

T'ai-shan-ho, augen-gneiss near 5 

unconformity near 5 

Tai-yang, stratigraphic sequence in 68 

T'ai-yuan-fu basin, character and history of 108-109 

Ta-ku-shan quartzite, occurrence of 13 

Ta-miau-ssi, Paleozoic fossils collected near 54 

Tangential compression, discussion of 123-133 

T'ang-hien stage of physiographic development, age 

and character of 103 

Ta-ning-ho, Permo-Mesozoic rocks along 84 

Tarim basin, continental element in 120 

Ta-tung-fu, section at 82-83 

Sinian limestones near 33 

Ta-tung-fu basin, character and history of 108-109 

Ta-yang limestone, basal rock of 9 

character of 8-9 

contact between Sinian and 9 

correlation of 8 

flint lamina: in 9 

local application of name 11 

section of 10 

stratigraphic equivalents of 8 

thickness of 9 

type locality of 8 

unconformities above and beneath 9 

Tchersky, I. D., cited on convergence of axial trends 

in Irkutsk 25 

Temperature, effect of, in diastrophism 126, 130, 132 

Tenasserim valley Burmah, Carboniferous rocks in 74 

Tertiary period, deformation during 96-1 13 

Tertiary-Cretaceous peneplain in northern Siberia, 

remnants of 101 

Tethys, limits and age of 80-81, 116, 123 

Thrust, direction of 132 

effects of 116 

source of, specifically 128 

sources of 125-133 

Tibet, altitudes and structure in 112-1 13 

Carboniferous limestone in 73, 74 

Devonian rocks in 59-63 

granitic intrusions in 92 

metamorphic rocks in 20-23 

Paleozoic diastrophism in 66 

rivers of, features of 112 

tangential compression in 123 

Tien-shan, peneplain represented in summits of 102 

To-lai-shan, Devonian and Carboniferous lime- 
stones in 74 

Tong-tien-ch 'ing, section at 75-76 

Tdu-ts'un slates, character and thickness of 8 

stratigraphic place of 4, 8 

unconformity below 4 

Trans-Baikalia, physiographic character of 110 

stratigraphic history of 121-122 

zone of sedimentation in 121-122 

Trenton limestone, Chinese equivalents of 55 

Triassic. See Pcrmo-Triassic. 

Triassic fossils, occurrence of 86 

Tsi-nan limestone, character, thickness, and dis- 
tribution of 42-43 

section of 10 

stratigraphic equivalents of 37, 43 

type locality of 42 

Ts'in-ling-shan, Carboniferous limestones in 73 

deformation of 97 

Devonian rocks and fossils in 58 

elevation of, age of Ill 



PAOB. 

Ts 'in-ling-shan — Continued. 

fossils collected in 57 

geologic history of 90-93 

igneous intrusions in 91-92 

Jurassic rocks in 87 

Proterozoic rocks of 14-20, 26 

Silurian and Devonian rocks in 56 

structure of Ill 

zone of deposition in 122 

Ts'in-ling peneplain, age and character of 103 

remnants of Ill 

Tung-ting sandstone, stratigraphic place of 53 

Tung-won beds, stratigraphic equivalents of 37 

Tung-yu limestone, character and thickness of ... . 8 

stratigraphic place of 4, 8 

Unakas, probable existence of, in Asia 102-103 

Uplands, monoclinal flexure defining 116 

persistence of 115 

Vaginoceras limestone, Chinese equivalents of 55 

Vaikrita system, character, thickness, and distribu- 
tion of 23, 46-47 

Vogelsang, Karl, cited on Permo-Mesozoic rocks 84 

Walcott, CD., cited on pre-Cambrian fossils 7 

Warping, age and effect of 98-99, 105 

relation of faulting to 107 

Wei valley basin, character and history of 108-109 

Weller , S. B . , cited on fossils of Sin-t 'an formation . . 55, 57 
Willis, Bailey, cited on flint lamina? in Siyeh lime- 
stone, Belt formation, Montana 9 

Wu-shan limestone, fossils of 72 

occurrence and distribution of 71-73 

relations of 74 

stratigraphic equivalents of 54 

Wu-t'ai district, structure in 89-90 

Wu-t'ai-hien, Hu-t'o rocks in 7 

Wu-t'ai period of orogeny, age of 28 

Wu-t'ai-shan, location of 4 

overthrust in, direction of 123 

rocks of 3, 4, 5, 6, 7, 43-44 

zone of deposition in 122 

Wu-t'ai system, age of 3, 4, 25 

analogy between Huronian and 1,3, 6-7 

character of 25-26 

correlation of 3,4 

deformation and intrusion of 26 

distribution of 4-7 

rocks composing 4-7 

subdivisions of 4 

thickness of 26 

unconformities within 5, 28 

unconformities above and below 4 

Yang-tzl-kiang, Devonian rocks along 54 

glacial deposits on 39 

Paleozoic rocks along 55 

Permo-Mesozoic strata along 83-84 

Sinian system on 44 

structure along 92, 106 

Yang-tzl stage of physiographic development, age 

and features of 99, 103, 1 1 1 

Yung-ning sandstone, stratigraphic equivalents of . . 43 

Y&n-nan, fossils found in 65 

Permian or Triassic rocks in 85-86 

Proterozoic strata in • 29 

Yfi-tsai-shan, rocks on 15 

Zaravchan range, fossils from 64 

Zorobad basin, physiographic history of 1 10 



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